megaliths are large stone structures or group of stating stones that are believed to have religious significance. Megaliths are classified in to groups known as "dolmens" or "menhirs". Domlens are thought of to be tombs, and menhirs are large stone standing structures, These are important because they can tell us about the past and sometimes they tell us about astronomical things. Some people believe that they had magical powers and you can feel a sensation when you come close to them.

http://upload.wikimedia.org/wikipedia/commons/5/5b/Megaliths_Aswan_Nubia_museum.JPG