Deep beneath the hills near Ella lies Nil Diya Pokuna, a little-known underground pond whose clear blue water appears only under artificial light inside the cave. Hidden nearly 80 meters below the surface, this cave system is wrapped in legends of King Ravana and ancient Sri Lankan folklore.
Nil Diya Pokuna is not a conventional sightseeing location; visiting it involves a physically demanding descent into a natural cave system. Dark tunnels, echoing caverns, and the glimmer of pure blue water make this one of the most intriguing (and challenging) destinations on the island.
What is Nil Diya Pokuna?
“Nil Diya Pokuna” translates to “Blue Water Pond”.
It’s a natural underground water body found inside a deep cave complex in Karandagolla, near the famous Ravana Falls in Ella.
The pond’s name comes from its vivid, sapphire-blue hue – water so clear and still that it seems to glow. Because sunlight never reaches the pond, its color appears unusually deep when illuminated by headlamps or torches.
Local residents believe this cave system has existed for centuries, though its exact age has not been scientifically documented.
Nil Diya Pokuna Location
📍 Location: Karandagolla, Ella (Uva Province, Sri Lanka)
🗺️ Distance: About 5 km from Ella Town
📏 Depth: ~80 meters underground
The Nil Diya Pokuna, situated 80 meters deep within a mountain cave in Karandagolla, can be accessed via two separate entrances. The better-known one is located in a forest reservation in the area, while a villager discovered a second entrance on private property about three years ago. However, many had reached Nil Diya Pokuna via both ways.
Access to the Nil Diya Pokuna, known as the ‘Hulan-guhawa’ (wind-give-in), is not through the well-known passageway used by travelers. The Earlier passageway is said to have been deserted as it is excessively unsafe.
The ‘Hulan-Guhawa’ entrance is baffling, as a consistent stream of wind continues blowing out of it. This wind blowing could be experienced up to a depth of about 3-4 meters into the gully. From that point, the wind weight becomes ordinary.
The underlying drop was steep, and you needed a rope to climb down. After inching and slithering for a couple of minutes, you will create a passageway that allows you to stand and walk in. However, the floor was so dangerous with Bat’s crap. At that point, you will enter an expansive arch-like structure, which feels unexpectedly vast compared to the narrow passages leading into it.
As you cross through it and continue down, you will reach the pond. The pond itself is in a vault around 30 meters wide. The full extent of the pond is unknown, as parts of it extend beyond visible cave walls and have not been formally mapped.
The Legend Behind the Pond
According to the Ramayana, the ancient Indian epic, King Ravana once ruled a golden kingdom in Lanka. Local folklore linked to the Ramayana associates the Ella cave region with Princess Seetha, though there is no historical or archaeological evidence connecting Nil Diya Pokuna specifically to this story.
While no scientific evidence supports this tale, the legend lends the place a magical air. Locals believe the caves were once part of a vast network of tunnels built by Ravana himself—a narrative that remains part of local oral tradition rather than documented history.
(The celebrated Indian epic “Ramayanaya” provides a detailed account of Rawana’s Lankapura kingdom and how Princess Seetha was kept hidden within it.)
Why Visit Nil Diya Pokuna?
Nil Diya Pokuna is more than just a tourist attraction; it’s an experience that combines adventure, history, and natural beauty. Here’s why it should be on your Sri Lanka bucket list:
- Thrilling Descent: Entering Nil Diya Pokuna involves descending into darkness, where the air becomes cooler, and the atmosphere takes on a mystical feel.
- Crystal-Clear Waters: The underground pond’s water is evident with a deep blue hue, creating an ethereal sight.
- Adventurous Exploration: The cave system remains largely unexplored, making it a thrilling spot for those with an adventurous spirit.
- Off-the-Beaten-Path: Unlike crowded tourist spots, Nil Diya Pokuna offers a serene and untouched environment.
- Unique Adventure: The combination of hiking and caving makes it a thrilling experience for adventure seekers.
- Cultural Significance: The site’s connection to the Ramayana adds a layer of cultural and historical intrigue.
- Photography Opportunities: Photography is possible, but challenging, due to darkness, moisture, and limited space for equipment.
Route from Colombo to Nil Diya Pokuna
- By Bus: Come from Colombo to Wellawa by bus. Then, you can go along the Wellawaya-Ella-Kumbalwela highway and reach Nil Diya Pokuna.
- By Train: Come from Colombo to Ella by train. Nil Diya Pokuna can be reached by bus from Ella along the Wellawaya-Ella-Kumbalwela highway.
Route from Badulla to Nil Diya Pokuna
- By Bus: Start by bus from Badulla to Ella. Buses run regularly on this route. The distance between Badulla and Ella is relatively short, and the journey typically takes around 30 minutes. Once you arrive at Ella, you can hire a tuk-tuk or walk to the Nil Diya Pokuna.
- By Train: Start by train from Badulla to Ella. Trains are available from Badulla to Ella, offering beautiful views of the Sri Lankan countryside along the way. The train journey from Badulla to Ella is short and usually takes around 30 minutes.
- By Tuk-Tuk: Start by hiring a Tuk-Tuk in Badulla. You can find Tuk-Tuks at various locations around town, and it’s a good idea to negotiate the fare with the driver to ensure they can take you to Nil Diya Pokuna.
Best Time to Visit Nil Diya Pokuna
The best time to visit Nil Diya Pokuna is during the dry season, from December to March. This period has less rainfall and clearer paths, which makes the caves more accessible.
The morning is the ideal time for this adventure.
Guidelines and Safety Tips to Visit Nil Diya Pokuna
- Follow Your Guide’s Instructions
Your guide knows the terrain best—listen carefully to their directions to ensure a safe and insightful experience. - Be Aware of the Risks
The cave environment includes sharp drops, jagged rocks, and slippery surfaces. Stay alert and proceed with caution. - Prepare for Confined Spaces
The trek involves navigating approximately 1 km through narrow, dark passageways. Be mentally and physically ready. - Pack Light and Smart
Carry only the essentials in a small, secure backpack to move easily through tight spaces. - Stay Focused and Cautious
Pay attention to your surroundings at all times to avoid slips, trips, and other hazards. - Handle Camera Gear with Care
If you plan to take photos, ensure your equipment is secure and can handle muddy, wet conditions. - Expect to Get Muddy
The cave floor can be damp and dirty – dress appropriately and embrace the adventure. - Don’t Rush the Journey
The terrain is challenging so that progress may be slow. Take your time and prioritize safety over speed. - Allocate 3–4 Hours
Plan for a total trip duration of 3 to 4 hours, including descent, exploration, and return.
Important Notes
- Nil Diya Pokuna should be entered only under official guidance.
- Unauthorized visits are strictly prohibited.
- There are no restrooms, lighting, or safety railings underground.
- Children and elderly visitors should not attempt this activity.
- Photography is allowed, but flash may disturb cave wildlife.
Things Seasoned Visitors Quietly Do
- Wear thin gloves – not for warmth, but for gripping damp rock
- Bring a backup headlamp, even if your guide has lighting
- Use shoes with hard toe caps (soft trainers absorb water and lose grip)
- Remove dangling straps or accessories – they catch on rock edges
- Eat after, not before — the climb back up is more strenuous than the descent
What the Blue Really Is: A Ground-Level Explanation
One detail often overlooked in online descriptions is why the water looks blue despite complete darkness.
Based on observations from local guides and cave explorers familiar with Ella’s limestone geology, the blue appearance is not caused by light reflection or algae, as many assume. Instead, it comes from a combination of:
- Exceptional water clarity (low sediment and organic matter)
- Mineral-rich bedrock, which subtly absorbs warmer color wavelengths
- Artificial light sources (torches or headlamps) reflecting off a perfectly still surface
Because the pond is undisturbed by wind, surface ripples, or sunlight, the water behaves like a mirror — amplifying cool tones and giving the illusion of a glowing blue pool. This effect disappears if the water is disturbed.
👉 Traveler tip:
If you splash the water or drop an object, the blue appearance fades temporarily. Many first-time visitors mistake this for “changing color,” but it’s simply the physics of still water in total darkness.
“The Moment That Catches Most Visitors Off Guard”
Almost everyone prepares for the descent — ropes, darkness, bats, slippery rock.
The Moment That Catches Most Visitors Off Guard
Almost everyone prepares for the descent – ropes, darkness, bats, slippery rock.
What most people don’t expect is the silence.
Once you reach the lower chambers near the pond, outside sounds vanish completely. Even voices feel muted, as if the cave absorbs them. Several guides intentionally switch off all lights for a few seconds – not as a thrill tactic, but to let visitors understand how isolated this space truly is.
For many, this is the most intense part of the experience — not fear, but a sudden awareness of being completely removed from the surface world.
This isn’t something photos or videos convey. It’s one reason Nil Diya Pokuna leaves a lasting impression even on travelers who’ve done caves elsewhere in Asia.
Why Guides Are Extremely Strict – and Why Locals Support That
Unlike many adventure sites in Sri Lanka, local residents strongly support restricted access to Nil Diya Pokuna.
The reason is practical, not political.
- The cave’s airflow system (including the Hulan-Guhawa) is delicate
- Small collapses have occurred in lesser-known side tunnels
- A single careless act — removing rocks, marking walls, swimming — could permanently damage the cave ecosystem
Older residents of Karandagolla recall a time when curious visitors entered without guidance, leading to injuries and near-fatal incidents. Since controlled access began, there have been no major recorded accidents.
Who Should Not Visit Nil Diya Pokuna
This place is extraordinary — but it’s not for everyone.
Nil Diya Pokuna may not be suitable if you:
- Experience claustrophobia, even mildly
- Expect a scenic walk or viewpoint-style attraction
- Are uncomfortable with complete darkness
- Have knee, ankle, or lower-back issues
- Prefer independent exploration without guides
FAQ
1. Is Nil Diya Pokuna dangerous?
Nil Diya Pokuna involves real physical risk if entered without proper guidance. The cave includes steep drops, slippery surfaces, and complete darkness. With an experienced local guide, appropriate equipment, and good physical fitness, the risk is manageable — but it is not a casual or beginner-friendly attraction.
2. Can you swim in Nil Diya Pokuna?
Swimming is not permitted. The water depth is unknown, visibility changes with disturbance, and there are no safety provisions. Guides strictly prohibit entering the water to protect both visitors and the cave environment.
3. Why does the water in Nil Diya Pokuna look blue?
The blue appearance is visible only under artificial light. It results from exceptionally clear, still water reflecting cool light tones inside a completely dark cave. The color is not permanent and fades if the water surface is disturbed.
4. How long does it take to reach Nil Diya Pokuna underground?
From the cave entrance, reaching the pond usually takes 45 to 60 minutes, depending on group size, conditions, and individual fitness. The return climb often takes longer due to fatigue.
5. Is Nil Diya Pokuna suitable for children?
No. Due to narrow passages, steep descents, and lack of safety infrastructure, Nil Diya Pokuna is not suitable for children. Most guides also discourage visits by elderly travelers or anyone with mobility issues.
6. Do you need special permission to visit Nil Diya Pokuna?
Yes. Entry is allowed only with authorized local guides. Independent or unguided access is restricted due to safety concerns and environmental protection.
7. Is Nil Diya Pokuna connected to Ravana Cave?
There is no proven geological or archaeological evidence confirming a connection between Nil Diya Pokuna and Ravana Cave. The association comes from local folklore rather than documented research.
8. What should I wear to visit Nil Diya Pokuna?
Wear long pants, a long-sleeve top, shoes with strong grip, and clothing you don’t mind getting dirty. Thin gloves are recommended for gripping wet rock surfaces. Avoid loose accessories or backpacks with dangling straps.
9. Are bats inside Nil Diya Pokuna?
Yes. Bats inhabit parts of the cave system. They generally avoid human contact, but visitors should remain calm, avoid loud noise, and never use flash directly at wildlife.
10. Is Nil Diya Pokuna worth visiting if you’re not an adventure traveler?
Probably not. This site is best suited for travelers interested in cave exploration and physically demanding experiences. Those looking for scenic views or easy attractions may find the effort disproportionate to the visual reward.
11. Can Nil Diya Pokuna be visited during the rainy season?
Visits during heavy rain are strongly discouraged. Increased water flow can make cave floors slippery and unstable. The dry season offers safer conditions, though final decisions are usually made by local guides on the day.
12. How does Nil Diya Pokuna compare to Ravana Cave?
Ravana Cave is easier to access and suitable for most visitors. Nil Diya Pokuna is deeper, darker, and requires technical guidance. The two experiences are very different, despite being geographically close.
13. Is photography allowed inside Nil Diya Pokuna?
Photography is allowed, but challenging. Moisture, darkness, and confined spaces limit camera use. Tripods are impractical, and flash should be used cautiously to avoid disturbing wildlife.
Videos
Final Thoughts
Nil Diya Pokuna is a testament to Sri Lanka’s rich natural and cultural heritage. Whether you’re drawn by the legends, the adventure, or the sheer beauty of the place, this hidden gem promises an unforgettable experience. So, pack your bags, lace up your hiking boots, and get ready to explore the mystical depths of Nil Diya Pokuna – one of Sri Lanka’s least-accessible and most carefully controlled natural cave sites.
If you’ve visited Nil Diya Pokuna, please share your experience in the comments below!
By Tour My Lanka Editorial Team
– promoting sustainable and authentic travel across Sri Lanka.
Last Updated: January 2025
Images in this article are for illustration purposes and sourced from royalty-free platforms such as Pixabay and Unsplash.
Disclaimer: Ticket prices, opening hours, and transportation costs mentioned in this article may change due to seasonal or administrative updates. Please confirm with the relevant local authorities before visiting.
