Lasers reveal prehistoric Irish monuments that may have been 'pathways for the dead'

A lidar image of the Irish countryside showing monuments detected.

Lasers have revealed hundreds of previously undetected prehistoric monuments, including five rare ones, clustered in a swath of farmland in the Irish countryside.

Archaeologists discovered the monuments in Baltinglass, a town in County Wicklow in eastern Ireland, using lidar (light detection and ranging), a technique in which an aircraft flies overhead while a machine shoots laser pulses toward the ground. These pulses hit objects and then bounce back, helping researchers map the landscape's topography.