Like the Giant's Tomb, the Knight's Tomb is a wooded hill encircled by the Semois.  This viewpoint can be seen from Herbeumont Castle, another must-see site of the Semois Valley. So you can kill two birds with one stone with a visit!

 

A legendary story is also behind the site's name: that of a foreign lord who leapt into the void over the Semois to join an amazing nymph he thought he had seen on the other side. He crashed to the ground a few dozen metres below and was swallowed up by the hill.