Bastioned forts of this type were engineered specifically to resist artillery: their angular, projecting points, or bastions, were designed to eliminate blind spots and allow defenders to cover every approach with overlapping fields of fire. That such a structure once occupied this stretch of Dublin parkland is easy to miss entirely, yet the cartographic record makes it plain.

The fort was constructed in the early part of the eighteenth century, positioned just inside the Dublin Gate at the south-eastern end of the park. By 1757 it was prominent enough to be labelled 'THE FORTIFICATION' on John Rocque's detailed map of County Dublin, one of the most significant cartographic surveys of the period. Taylor's map of 1816, which surveyed the environs of Dublin at a scale of two inches to the mile, still shows the upstanding remains of the structure, suggesting the earthworks were largely intact well into the nineteenth century. That changed in September 1834, when the landscape architect Decimus Burton oversaw a programme of improvements to Phoenix Park. Among the works carried out under his direction was the levelling and filling of the star fort, along with the replacement of open drains with underground ones. The Ordnance Survey six-inch map published in 1837 still carries the annotation 'STAR FORT', a quiet acknowledgement of what had recently been erased.

The site today is occupied by sports grounds, and there is nothing visible at ground level to indicate what lies beneath. For anyone interested in the archaeology of the place, the most rewarding approach is through the maps themselves. Rocque's 1757 survey and Taylor's 1816 map both show the fort at different stages of its existence and can be consulted through the digital collections of the National Library of Ireland. On the ground, the south-eastern approach to Phoenix Park near the Dublin Gate gives some sense of the fort's original position, even if the landscape has been entirely remodelled since Burton's interventions.