Jokulsarlon Deep Dive
Jokulsarlon is the proglacial lagoon at the snout of Breidamerkurjokull, itself an outlet of Vatnajokull on Iceland's south coast. Sixty years ago it didn't exist. Today it covers around 25 km2 and is one of the most visited natural sites in Iceland.
How it formed
The Breidamerkurjokull glacier reached the sea around 1894. As Iceland warmed in the 20th century, the snout retreated inland and a basin opened. By the early 1970s the lagoon had formed and started filling with icebergs calved from the retreating face. The depth — over 200 m in places — is unusual for a glacier lagoon and makes it the deepest lake in Iceland.
What you see
Icebergs calved from the glacier sit in the lagoon for weeks before drifting out through the short river channel into the Atlantic. Many re-stand themselves on the black-sand beach across Route 1 — the "diamond beach" of every Iceland photo essay.
How to visit
The lagoon is on Route 1 (the Ring Road) about 5 hours from Reykjavik. You can simply pull off the road and walk to the shore. For boat tours:
- Amphibious boat tours — 30-40 minutes among icebergs, May to October.
- Zodiac tours — smaller, faster boats that go closer to the glacier face.
- Kayak tours — independent operators, advance booking essential.
Risks and visitor management
The icebergs roll. Walking on a beached one has killed visitors. The beach itself has dangerous sneaker waves. Ranger patrols are stricter each year. Cross the road only at marked crossings — Route 1 has had fatal accidents involving distracted pedestrians.
Future
The lagoon is growing as the glacier retreats. Estimates suggest it will eventually reach roughly 40 km2 before stabilising as the ice front retreats to higher ground. Whether the diamond-beach phenomenon continues depends on the iceberg supply, which will reduce as the glacier gets smaller.
Crowds
Summer mid-days are insane. Sunrise and sunset are calm. Winter visits can be extraordinary — fewer tour buses, longer twilight light, the aurora overhead. Check road and weather conditions in winter before driving.
Explore on the map
Find Jokulsarlon and the nearby Heinabergslon, Fjallsarlon and the diamond beach on the interactive map. Each lagoon has its own character — Heinabergslon for solitude, Fjallsarlon for compact calving views.