The North East has many rivers both huge glacial rivers and also some of the best salmon rivers in the country. Jökulsá and Skjálfandafljót are two huge glacial rivers that start in Vatnajökull and run all the way to the sea Jökulsá more than 200 km. Jökulsá has gorged out the largest canyon in Iceland, 25 km. long and more than 100 m. deep in some places. Dettifoss, the most powerful waterfall in Europe is one of the attractions of the canyon but there are many. Small rivers and streams can be found anywhere much like in most other parts of the country. There is trout fishing in many of the rivers and permits easily obtainable except for the salmon rivers and the best trout rivers that are booked in advance.