7. Fingal Cave (Scotland)
Located on the inhibited island of Staffa, this sea cave is made entirely out of hexagonally shaped basalt columns. Known for its high arched roof, Fingal Cave looks like a natural cathedral.
Fun Fact: Due to its arched roof and size, the echoes of the waves make the cave resonate with eerie sounds; for this reason, the cavern’s Gaelic name is An Uaimh Bhinn, meaning “the melodious cave.”