Underwater & Underground

Explore the amazing ways that geothermal and volcanic activity has shaped our landscape!  We will take you underwater and deep underground for the most unusual views of what happens when the ferocious forces unground meet the surface of our world.

We will first take you snorkelling through hot springs at the bottom of Lake Kleifarvatn. Lake Kleifarvatn is hidden within a stunning volcanic landscape just 30 minutes outside of Reykjavík. Don’t let the term “hot springs” fool you though. The lake is still very cold and you will put on a dry suit in order to stay warm in this remote lake.

Upon entering the lake you can see the white and yellow sulfur deposits on the lake floor. When we swim closer, you’ll begin to sense the environment around you changing as you approach the gas emanating from below the lake’s floor.  We’ve heard this sensation described as similar to ‘snorkeling in a glass of Champagne’—the fact that you are snorkeling in a caldera is also impressive enough!

When back on land we will enjoy some refreshments at the shore before moving on to Seltún, a nearby high temperature geothermal area on land. In Seltún we will walk along the boiling mud pots and colorful sulfur deposits.

We will then make our way to the fantastic lava tube called Leiðarendi where you will descend into the extensive systems of lava caves.  These caves, or tubes, were created during volcanic eruptions as molten lava flowed while also cooling at the surface.   These tubes now form an incredible underground world and are safe for exploration. You will be surrounded by fantastically odd rock formations and your flashlight will bring the phenomenal display of colors to light.


Tour Details


1. April – 30. September



Participants must:

  • have read and signed the Snorkeling Silfra Medical Statement (view HERE)
  • sign our liability release form at the start of the tour (view HERE)
  • Be at least 150cm tall
  • Be at least minimum 45kg / maximum 120kg
  • Be at least 16 years of age
  • Be comfortable in water and be able to swim
  • Be physically fit
  • Be ready to wear a sometimes tight & constricting dry suit
  • Be able to communicate in English
  • Not be pregnant

All participants age 60 or older and all participants under a doctor’s care for any ongoing medical condition must have our medical form signed by their physician. The Medical form can be viewed and downloaded HERE.




8-9 hours

Min / Max:

Minimum 2 snorkelers / Maximum of 6 snorkelers per snorkel guide

Maximum 8 cavers per cave guide

Please bring:
  • Long underwear
  • Thick socks
  • Extra warm clothing for the cave
  • Sturdy shoes
  • Contact lenses if you wear glasses
  • Guided snorkelling trip in lake Kleifarvatn
  • All necessary snorkelling equipment
  • Hot vegan and gluten-free soup and light refreshments at the lake’s shore
  • Stop at geothermal area Seltún
  • Guided cave tour
  • All necessary caving equipment
  •  Hiking shoes
  • Long underwear

10:00- 10:30 hotel pick up in Reykjavík

Book this tour now!