Iceland: Borgarvirki
Borgarvirki is a volcanic plug made from a lava flow that solidified into basalt columns that rise above the surrounding terrain (similar to the Devil’s Tower in the USA). But it has also been used as a fortress by early Viking settlers who additionally fortified some walls and approaches. Located in the south of the Vastness Peninsula, Borgarvirki has walls that are i10-15m high and 177m above sea-level. The panoramic views from the top are top-notch.
