Sruhaun hillfort was only discovered in 2013 when archaeologist James O'Driscoll of University College Cork spotted its faint outline using cutting-edge LiDAR technology. Perched on the southern spur of Tuckmill Hill, this ancient enclosure overlooks the town of Baltinglass just 900 metres away, whilst sharing the landscape with two other hillforts: Rathnagree to the north and Rathcoran to the east-northeast.

The hillfort consists of a roughly circular earthwork enclosing an area of about 1.43 hectares, though its low bank and shallow internal ditch are so weathered they're barely visible to the naked eye. The enclosure measures approximately 129 metres across from northeast to southwest and 152 metres from northwest to southeast. A 2012 geophysical survey revealed what appears to be a 10-metre-wide opening on the northern side, possibly an original entrance, though this remains unconfirmed. The eastern section of the site is bisected by an old townland boundary wall, now partly obscured by more recent field clearance.

In 2015, Professor William O'Brien led an excavation that revealed fascinating details about the site's construction. His team uncovered evidence of two ditches inside the remains of a stone bank, along with signs of intense burning at the bank's base. Charcoal samples were recovered for radiocarbon dating, though no artifacts were found during the dig. This mysterious hillfort represents one of Ireland's prehistoric settlements, detected through modern technology yet built by ancient hands in a landscape that has witnessed human habitation for millennia.