Hvítserkur, Iceland

Hvítserkur is a 15 m high basalt stack along the eastern shore of the Vatnsnes peninsula, in northwest Iceland.

The sea has eroded what was once a volcano, leaving only the stack behind. The base of the stack has been reinforced with concrete to protect its foundations from the erosion of the sea. The rock has two holes at the base, that makes it look like an animal of some sort or perhaps a dragon who is drinking.

Several species of birds, such as gulls and fulmars, live on at Hvítserkur. It is half-white from the guano deposited on the rock. That is how the rock got its name Hvítserkur (white shirt in Icelandic). Hvít meaning white and -serkur meaning a long shirt.

and its name ("white shirt" in Icelandic) comes from the color of the guano deposited on its rocks.

Dun Briste Sea Stack, Ireland

Dun Briste (Gaelic for Broken Fort) is an incredible, 45 metres (150 feet) tall sea stack in Ireland.

Dun Briste and the surrounding cliffs were formed around 350 million years ago, when sea temperatures were much higher and the coastline at a greater distance away. Dun Briste was once part of the mailand. There was an arch leading to the rock, but it is believed to have collapsed during very rough sea conditions in 1393. This is remarkably recent in geological terms.