At Nojimazaki, the southern tip of the Boso peninsula, a white lighthouse stands on a rocky point above the Pacific. It was one of the first Western-style lighthouses in Japan, built in the late 1860s by a French engineer, and its gallery looks out over a coast of black rocks, surf and wide horizons. The stop sits a little way inland, in the hills between Minamibōsō and Tateyama.
The southern Boso has a mild climate, warmed by the Kuroshio current, and flowers bloom here in the depths of winter. The Boso Flower Line, the coast road from Tateyama to Shirahama, runs past fields of rapeseed, stock and poppies, and in January and February, when the rest of Japan is cold and grey, the fields are a riot of colour.
Shirahama is the home of the ama, women divers who for centuries have gathered abalone, turban shells and seaweed from the seabed without breathing gear. Their tradition is celebrated in a summer festival, when the divers carry torches into the sea at night.
For a swim, the beaches around Shirahama and the southern coast are open in July and August, with lifeguards and flags. The surf can be strong on the Pacific side, so swim only in designated areas.
The riding on the southern Boso is gentle and scenic, with coast roads, hills and little traffic outside the holiday season. The roads inland are narrow and winding, with forests and small villages. Tateyama, twenty minutes up the coast, handles fuel. Down here, eat where the boats tie up: the small harbour restaurants serve whatever came in that morning, often with a view of the divers' huts.