The Carrowkeel/Keshcorran Megalith complex is located west of Lough Arrow just outside the little town of Castlebaldwin and is the sight of the largest concentration of passage tombs in Ireland. These passage tombs (fourteen in all) are sunken burial chambers made of large limestone slabs, topped with huge piles (cairns) of rocks. These tombs are most usually located high upon hills and mountains and dot the landscape around Sligo County, forming a larger network of ancient sites whose mysterious origin is still largely debated.
The Carrowkeel complex, believed to have been constructed between 3000 and 2000 BC, remained in use until 1500 BC. The cairns, built of limestone with interior chambers roofed with large limestone slabs, range in size from 25 to 100 feet in diameter. The site was used in Christian times as a burial place for unbaptised children. Carrowkeel was rapidly and very poorly excavated in 1911, often with the use of dynamite, and each of the cairns was assigned an identification letter.