Built in the 14th Century the castle was originally intended to monitor the crossing of the River Usk.

Watch seals basking on the rocks at low tide or snoozing in the water at high tide. Keep an eye out for the regularly seen harbour porpoises beneath diving gannets. At Worms Head experience the sights, sounds (and smells!) of nesting sea birds between April and July, such as kittiwakes, guillemots and razorbills. If you are lucky you sometimes encounter common dolphins in the warmer months of the year, May to September. On some trips you also get to see Manx shearwaters, fulmars, and peregrine falcons. You also see a variety of different jellyfish, occasionally sunfish and rarely even turtles!

The best way to explore the city and Bay, hear the history, see the sights on board Princess Katharine.