"Svartifoss (Black Fall) is a waterfall in Skaftafell in Vatnajökull National Park in Iceland, and is one of the most popular sights in the park. It is surrounded by dark lava columns, which gave rise to its name. Other well-known columnar jointing formations are seen at the Giant's Causeway in Northern Ireland, Devil's Tower in Wyoming, USA and on the island of Staffa in Scotland. There are also similar formations throughout Iceland, including a small cave on the beach of Reynisdrangar.
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.
These basalt columns have provided inspiration for Icelandic architects, most visibly in the Hallgrímskirkja church in Reykjavík, and also the National Theatre."
"Gullfoss (Golden Waterfall) is an iconic waterfall of Iceland offering a spectacular view of the forces and beauty of untouched nature. Gullfoss is part of the Golden Circle tour, located in South Iceland on the Hvítá (White) river which is fed by Iceland´s second biggest glacier, the Langjökull. The water plummets down 32 meters in two stages into a rugged canyon which walls reach up to 70 meters in height. On a sunny day shimmering rainbow can be seen over the falls." http://www.gullfoss.is/about-gullfoss/
"Sveinstekksfoss is a modest waterfall along the stream Fossá just northeast of the town of Djúpivogur. The falls crash 49 feet into a narrow gorge carved into a part of the incredibly unique layered basalt flow formations which permeate this area of the island, with the stream then snaking through the narrow twisting gorge to a small lagoon at its mouth. The twisting nature of the gorge ensures that the falls cannot be seen from stream level, and must instead be viewed from the cliffs along the rim of the canyon." http://www.worldwaterfalldatabase.com/waterfall/Sveinstekksfoss-14769/