Dettifoss is said to be Europe’s most powerfull waterfall. It is 44 m high and about 100 m wide (see the note w people on the other rim for scale). The water of the river Jökulsá á Fjöllum ("Glacial River on the Mountains") is always brown and muddy with silt. The waterfall is within the Vatnajökull National Park - Europe's largest NP - and below it is a long canyon with fascinating rock formations.