Bláfjallafoss, also known as the Blue Mountains, is a stunning mountain range in southwest Iceland. They are mainly famous for this specific river crossing, where the road F232 crosses a river in front of a waterfall.
This is in the highlands so you need a 4x4. Always check the depth of the water before crossing, it can change from day to day. The crossing is usually relatively easy and can be done on most 4x4s.