About 4000 BC, in the New Stone Age (Neolithic period), the first farmers arrived in Ireland. These people cleared openings in the forest and built permanent settlements with houses and farmland. When people in this age died, they were buried in tombs called megaliths. Many megaliths are left standing today, such as portal dolmens and passage tombs.The most famous megalith is Newgrange passage tomb in co.Meath.