Dettifoss

“The Myvatn region in the northeast of Iceland is volcanically active, its lunar-like landscape dominated by the Kafla volcano. There are lava fields and hot spring, such as Námaskaro, an area of spewing geysers and bubbling mud-pools. It is also a land of cascading waterfalls and deep gorges, the most spectacular waterfall, Dettifoss, lying along the Jökulsá á Fjöllum, the island's longest river. The river is fed by icemelt from the Vatnajökull and crosses over a high plateau which is scarred by lava flows, before it enters the sea at Oxarfjorour. There is also the impressive Myvatn ("Midge Lake"), which the area is named after.

Dettifoss is 144 feet (44 m) high and 330 feet (100 m) wide. They are considered to be the most powerful waterfalls in Europe, with an estimated 110,000 gallons (500,000 liters) of water passing over the falls every second. To the south is Selfoss, another cataract which is 33 feet (10 m) high, and the 90-foot (27-m) high Hafragilsfoss.

Below Dettifoss is a deep canyon, the Jökulsárglifúfur, which was gouged out by a series of catastrophic floods, the last occurring about 2,500 years ago. In the 1970s plans to build a hydroelectric power station were abandoned and the area is now protected.

Height of Dettifoss: 144 ft (44 m)
Width of falls: 330 ft (100 m)
Water flow of falls: 110,000 gal (500,000 l) per second”