Iama Island is the principle island of the Northern Isles. It is comprised of five extinct magma chambers, formed millions of years ago by dome volcanoes protruding through the seabed due to a hotspot. Over time, the severe weather conditions of the North Sea weathered them down to their current size. The island is characterised by having virtually no flat land, and being surrounded by deep ocean. What little flat land exists is mostly marshy, due to the impermeable nature of the volcanic bedrock. The seas around Iama are unrivalled in Ostentia for fish, with the Iaman Cod flourishing in huge numbers. The demand for this, both nationally and internationally, fuelled the construction of an international airport and large dock facilities. The capital of the Northern Isles, Torness, is located in the crater of one of the extinct volcanoes. The airport and dock were built at a new settlement on the south coast however, with links to Torness via a light railway and road, as most produce for shipping out comes from the ocean itself. The beaches in the north of the island are said by most to be particularly stunning. The black volcanic sand and clear water, with cold water reefs offshore, have made it a popular summer SCUBA diving area.