Located north of Foxrock Avenue and southwest of Dean's Grange Cemetery, this historic fortification was first documented in written records in 1900, when it received a brief mention in an anonymous publication. Today, visitors would be hard pressed to find any visible remains; the castle's exact location is believed to be somewhere near the shops at Dun Aengus, though even this is based on local historical knowledge rather than any surviving structures.

The castle appears on the 1843 Ordnance Survey six-inch map, marked but curiously unnamed, sitting at the end of a lane that branches off from Kill Lane. This cartographic evidence provides one of the few tangible links to the site's past, offering researchers and history enthusiasts a glimpse of where this defensive structure once stood. According to Liam Clare of the Foxrock Historical Society, the area has undergone significant development since the 19th century, with modern shops and buildings now occupying what was once castle grounds.

While the physical castle has been lost to time and urban development, its memory persists in historical records and local lore. The site represents one of many small castles that once dotted the Irish landscape, serving as defensive positions and symbols of authority during the medieval period. For those interested in Dublin's hidden history, the Deansgrange castle site offers a reminder that beneath the modern suburban landscape lie centuries of stories, even if the stones that could tell them have long since disappeared.