During April 2015, a team of archaeologists from Aberdeeen University uncovered what they believed to be the remains of a Pictish Promontory Fort on this sea stack, some 700 metres north of Dunnottar Castle. Early indications were that they had discovered the remains of a house, a fireplace and ramparts.
A glance at this Google Map of the area leaves one in little doubt that the Dunnicaer Stack was once attached to the mainland, probably by a long-fallen natural arch.
In all probability, like the crags at the western end of the neighbouring beach, which are already cut through by a natural arch, Dunnicaer was similarly connected to the shore in Pictish times. This would have provided relatively easy access to the fort via a ridge from the west. But in the centuries since, the arch has crumbled, isolating the stack which is now inaccessible without specialist equipment.
To visit the site, park at Dunnottar Castle, but instead of taking the steps down to the castle entrance, head left along the clifftops. You have the choice of a good, fairly direct track, or a narrow walkers path that hugs the cliff edge. From the point where you draw level with the Dunnicaer Stack, gentle grassy slopes lead down to the shore.