Pembroke Castle has a long and fascinating history, for it was around 1093 that Arnulf de Montgomery built the small inner bailey standing at the end of the promontory.
The late 12th century keep is both an outstanding feature and architectural novelty, for it has a massive cylindrical tower with an unusual stone dome. All the rooms are circular and the keep is nearly 80 ft high. This was the work of William Marshal, the man responsible for the wholesale reconstruction of the castle in stone in the late 12th/early 13th centuries. Another absorbing feature of the castle is the gatehouse, which had a complex barbican and no fewer than three portcullises.
Views from the top are tremendous and the castle's natural defensive position on a rocky promontory overlooking Milford Haven is immediately apparent. The main room on the second floor of the Keep has two windows embellished externally by dog tooth moulding and a carved head.
A battlemented flying arch inside the gatehouse is something of a puzzle, for it would appear to be of little use in repelling invaders who had actually forced entry into the castle. Still, the gatehouse is, overall, a mighty defence which proves the skill and the sophistication of military architects in medieval times.
Pembroke Castle is owned and managed by a private charitable trust.