The castle's documented history stretches back to 1540, when it was held by Sliocht Ríockard, before passing through various hands including Geffry beg mac Thomas Bourke in 1586. By 1622, the castle was already described as ruinous when it was granted to Sir William Parsons as part of James Riordan's former estate. The Civil Survey of 1654-56 recorded that Nicholas Haly of Tooreen owned the site, which then comprised not just the castle but also an orchard and a mill seat.

When surveyed in 1840, the castle presented a melancholic sight; only the north wall remained standing at about 25 feet high, along with partial sections of the east and west walls extending just eight feet from the corners. The structure measured 21 feet 2 inches from east to west, with walls four feet thick, though the complete absence of the south wall made it impossible to determine the building's original north-south dimensions. Set on remarkably level ground in a low plain, the castle was likely a tower house, as suggested by its depiction on 17th century Down Survey maps of South Liberties Barony and Carrigparson parish.

Today, visitors to Tooreen will find even less of the castle visible than what the Victorian surveyors documented. Modern satellite imagery from 2011-13 shows the ruins heavily obscured by tree cover, and recent orthophotography from 2018 and 2019 confirms that only fragments of the western portion remain upstanding, matching the deterioration noted in the 1840 survey. The castle's steady decline from inhabited fortress to romantic ruin reflects the broader patterns of abandonment and decay that affected many of Ireland's medieval and early modern fortifications following the upheavals of the 17th century.