Strýtan

1. J
2. F
3. M
4. A
5. M
6. J
7. J
8. A
9. S
10. O
11. N
12. D

Strýtan is a hydrothermal chimney in Eyjafjörður (north Iceland) — a 55 m tall limestone cone built up over ~10,000 years by ~75 °C freshwater venting from the seafloor. The chimney top sits at ~15 m, the base at ~65–70 m. It is the shallowest known active hydrothermal vent in the world and the only one at recreational diving depth. Saltwater fjord environment, sub-Arctic — 4–8 °C ambient outside the plume. Dive season is May–Sep when boat access from Akureyri is reliable; winter ice and weather effectively close the site. Drysuit mandatory.