Dartmouth Castle guards the narrow entrance to the Dart estuary from a rocky promontory about two kilometres south of the town. English Heritage manages the site, which includes the 15th century castle, a Civil War gun battery, and a Victorian coastal defence battery — giving the site three distinct layers of military history packed into a small headland.
The views from the castle walls are excellent: across the harbour mouth to Kingswear Castle opposite, up the river towards Dartmouth town, and out to sea. The walk from town along the waterfront path takes about 30 minutes and passes St Petrox church, which has served sailors and harbour pilots since Norman times. The castle interior is well interpreted and worth an hour.