The surrounding hills of the area is rich in archaeological and historical sites, including the Rathcoran passage structure. On the highest point of the Baltinglass Hill, north-east of the village, the passage grave from the Stone Age whose outer walls are finished in chalk not native to the area, is said on bright days to be visible from Kildare’s Curragh 48 km (30 mi) away. To the north end of the village on the weir of the River Slaney lies the ruins of an ancient monastery, Baltinglass Abbey, that has had many additions over the centuries; the original church is said to date from around 700 A.D.
The medieval Viscounts Baltinglass were from the Hiberno-Norman Eustace family, who also founded Ballymore Eustace. Their estates later passed to their cousin Sir Maurice Eustace, Lord Chancellor of Ireland 1660-1665. Sir Maurice did much to promote the development of the town, building a church, a school and a bridge, and encouraging new settlers.