Dettifoss, the plunging waterfall, is the volume richest waterfall of Europe and the largest of Northern Iceland. Dettifoss can be reached on different roads although in the winter there is only one way possible which is Road No. 862 (approach from the west side).
862 is paved but not attended by road services, therefore in the winter and/or fall and spring it can be closed due to dangerous road conditions, mainly ice or blowing snow. We were lucky and it was open for a couple of days when we were in the area. There is a parking lot (with a toilet :)). To get to the waterfall it is about a half a mile hike. The hike is a little bit tricky in winter as the trail is also not maintained, so we can highly recommend waterproof shoes.
In the summer the fall can be reached also from the north and from Road Nr. 864 (approach from the east side), which is generally closed in the winter time.
To be honest, after having seen Godafoss, Dettifoss did not impress us the same way. It is a huge and impressive waterfall but just not as beautiful as Godafoss. Also due to a lot of ice and also due to the fact the river was partially iced it just was not as forcefull as I had imagined. I guess it is absolutely dfferent in the summer after the snow melt. But please form your own opinion by checking out the pictures below.
About a mile before Dettifoss is Selfoss (not to be mistaken by the town Selfoss in Southern Iceland) which is smaller but also pretty cool. There is a trail to the end of the canyon with Selfoss, also pretty tricky in the winter but well worth the trip!