Tateyama faces west across the mouth of Tokyo Bay, and its bay is so calm that it has long been called Kagami-ga-ura, the mirror bay. On a still evening, Mount Fuji, across the water, is reflected in the sea, and the sunset turns the whole bay gold. Hōjō beach, in front of the town, is one of the best swimming beaches on the Boso peninsula, with calm water, fine sand and lifeguards in summer.
The town is crowned by a reconstructed castle on a hill, the seat of the Satomi clan, who ruled the southern Boso in the sixteenth century. Their story inspired the famous Edo-period novel Nansō Satomi Hakkenden, the tale of eight dog warriors, and the castle museum tells it.
Okinoshima, a small island connected to the shore by a sandbar, is a nature reserve with forest, rock pools and clear water, popular for snorkelling. Warm currents allow corals to grow here, close to their northern limit.
The riding around Tateyama is gentle and scenic, with coast roads and hills. The Boso Flower Line runs south along the coast towards Nojimazaki, and the roads inland are quiet. In summer, aim to arrive in the late afternoon, swim from Hōjō beach as the heat goes out of the day, and then sit on the sea wall for the sunset over Fuji. Fuel and food are close at hand in the town centre.