Iceland
A protected hydrothermal-vent diving region in Eyjafjörður, North Iceland, centred on Strýtan, the only accessible hydrothermal chimney divers can visit worldwide, and the nearby Arnarnesstrýtur vent field.
Eyjafjörður is one of Iceland's longest fjords, about 60 km long. Strýtan is a limestone hydrothermal chimney rising from 65 m to 15 m depth, formed over 10,000 years ago, described as the only such chimney accessible to scuba divers (others lie at 2,000-6,000 m); discovered in 1997. Since 2001 the site has been protected as Iceland's first underwater nature reserve. A second site, Arnarnesstrýtur ('Little Strýtan'), reaches 25 m depth. Source: Wikipedia (Eyjafjörður), Strytan Divecenter, X-Ray Mag.