Loughcrew or Lough Crew (, meaning lake of the tree) is an area of great historical importance near Oldcastle, County Meath, Ireland. It is home to a group of megalithic tombs dating back to the 4th millennium BC, which sit on top of a range of hills. The hills and tombs are together known as Slieve na Calliagh (Sliabh na Caillí) and are the highest point in Meath. It is deemed one of the four main passage tomb sites in Ireland and is a protected National Monument. The area is also home to the Loughcrew Estate, from which it is named.