Its walls are largely intact, complete with musket loops, D-shaped bastions, and a pedimented doorway at the centre of the north wall, yet the barracks and hospital that once occupied its interior have vanished entirely. In their place are overgrown terraces, a residential house just inside the main gateway, a Harbour Commissioners office on one of the lower levels, and at the northern end of the enclosing ordnance grounds, an Irish Army depot. A Victorian military building on the east side has been converted to residential use; a modern bungalow sits on the west. The fort has become, in effect, a small mixed-use neighbourhood contained within eighteenth-century defensive walls.

The fort was built between 1743 and 1749, and by 1750 the writer Charles Smith was describing it as carrying a battery of twenty pieces of ordnance. An 1804 military report gives a more precise picture: six 24-pounders on the lower level, thirteen guns on the middle battery, and one on the upper, with a barracks sitting above all three tiers and an additional battery facing landward. The site occupied three terraces rising from the shoreline, each connected by retaining walls and a central staircase. That configuration is still legible in the landscape today. The military role did not last. By 1837, Samuel Lewis was recording the fort as dismantled and already converted to a naval hospital, and Ordnance Survey maps from 1842 and 1902 confirm the shift, with the later map marking separate fever wards to the north of the main hospital buildings. None of those structures survive above ground.

The entrance to the fort is on the west side, marked by a piered gateway flanked by a D-shaped bastion to the south and a projecting section of wall to the north, both pierced with musket loops. The lower shoreline terrace retains its southwest and southeast bastions, and a slipway at the southwest corner is accompanied by a reconstructed boathouse. The upper terraces are overgrown, and the northeast bastion is poorly preserved, but the overall circuit of walls gives a clear sense of the fort's original star-shaped plan, a design intended to eliminate blind spots and allow defenders to cover every face of the fortification with flanking fire.