Svartifoss (Black Fall) is a waterfall in Skaftafell National Park in Iceland, and is one of the most popular sights in the park. It is surrounded by dark lava columns, which give rise to its name. The hexagonal columns were formed inside a lava flow which cooled extremely slowly, giving rise to crystallization. Similar well-known lava formations are seen at the Giant's Causeway in Northern Ireland, and on the island of Staffa in Scotland.
The base of this waterfall is noteworthy for its sharp rocks. New hexagonal column sections break off faster than the falling water wears down the edges.