Svartifoss

Svartifoss is a waterfall in the Skaftafell area of Vatnajökull National Park in southeast Iceland, framed on both sides and beneath by dark, tightly packed hexagonal basalt columns. The columns formed as a thick lava flow cooled slowly and evenly, contracting and cracking into the roughly hexagonal jointing pattern typical of columnar basalt, the same process that produced the Giant's Causeway and the columns at Reynisfjara; subsequent erosion by the stream feeding the waterfall exposed the columns in cross-section along the cliff face over which the water now falls. Its striking black, organ-pipe-like backdrop is reported to have inspired the design of the tiered facade of Reykjavik's Hallgrimskirkja church.