The Þórufoss waterfall is not well known among travellers and is kind of invisible unless you know where to look for it. It is near a side-road (48) of the road 36 to Thingvellir from Reykjavik. Until recently it was not marked so you had to know the location to find it, but now there is a sign by the road 48. Þórufoss was made famous in one of the episodes of Game of Thrones, where one of the dragons attacked a goat and flew away with it. Well, that was it's 15 seconds of fame.