Thridrangaviti Lighthouse

Þrídrangaviti Lighthouse (transliterated as Thridrangaviti) is a lighthouse 7.2 kilometres (4.5 miles) off the southwest coast of Iceland, in the archipelago of Vestmannaeyjar, often described as the most isolated lighthouse in the world.[1][2] Þrídrangar means "three rock pillars", referring to the three named sea stacks at that location: Stóridrangur (on which the lighthouse stands), Þúfudrangur, and Klofadrangur.[3] It was constructed in 1938 and 1939, with the lighthouse commissioned in 1942.[1] Originally constructed by hand without machinery, and accessible only by scaling the tallest of the three rocky stacks whose top is 36.576 metres (120 ft) above the sea.[1] It is now accessible by helicopter helipad.

Thridrangar Lighthouse, Southern Iceland, sits atop the tallest of three sea stacks.

Technical characteristics:

• The lighthouse building is about 30 metres (98 ft) from the sea [1]
• The building itself – a single story with a deck and the lamp on its roof – is 4 metres (13 ft) high[1]
• The light is 34 metres (112 ft) above the sea, which determines its "height of sight",[4] which is first visible from 16.7 kilometres (9.0 nautical miles; 10.4 miles)[1]

The lighthouse was built under the direction of Árni G. Þórarinsson, who recruited experienced mountaineers to scale the sea stack. Their climbing tools did not allow them to bite into the rock near the top, and there were no handholds, so they made a human stack - one man on his knees, a second atop him, and a third one climbing on the second one - for the final pitch.[5]