Morsárfoss

Morsárfoss is now recognized as the tallest waterfall in Iceland, dropping approximately 785 feet (240m) in several braided meltwater streams that can spread out to cover as much as a 600-foot breadth of a cliff band which previously was covered by a massive icefall in the Morsárjökull. The height of the falls cannot be accurately determined because the top of the falls is situated beneath the active glacier, and it falls into the bergschrund of the lower lobe of the glacier, so there is no way to tell where the bottom is either.
The falls were brought to attention in 2007 while surveyors were documenting glacial retreat in the area. The falls have likely existed - or rather have been exposed to the open air, rather than being hidden underneath the glacial ice - for decades. The cliff forming the falls has been exposed at least as far back as the 1940s, but whether the falls actually flowed down the exposed rock at that time (rather than flowing beneath the remaining icefall) is not clear.
There is currently no way to get close to the falls, so it must either be viewed via small aircraft, or on foot from a distance from the ridge to the south. On a clear day it may be possible to see a portion of the falls from Highway 1 west of Skaftafell, but at a distance of nearly 21 kilometers away it won't be a revealing view at all.