You cannot really see a kofun. That is the first lesson of Richu-tenno-ryo, one of the great keyhole-shaped tombs of the Mozu group in Sakai, south of Osaka. These are burial mounds built in the fifth century for the early rulers of Japan, shaped like a keyhole with a round back and a wide front, and surrounded by moats. The Richu mound is about three hundred and sixty metres long, among the largest in the country, and you walk around the water on a path, catching glimpses through the trees of a green hill that looks like a wooded island. From the ground it simply looks like a park.
To grasp the shape you have to look from above, and the nearby city offices have an observation deck for that purpose. The whole Mozu-Furuichi group was added to the UNESCO list in 2019. The tombs are still managed by the Imperial Household Agency, which restricts entry, so the stop is about walking the perimeter, reading the signs and imagining the labour involved, hundreds of thousands of people moving earth with baskets.
Sakai is a big city of nearly eight hundred thousand, with a long history as a free merchant port and a centre for knife-making that still produces some of the finest kitchen blades in the world. Fuel and food are easy everywhere, and the bay roads give you straightforward riding, though honestly this is dense urban Japan, with traffic lights, expressways, factories and little scenery. The Hanshin Expressway runs along the bay and costs tolls, and local roads are flat and steady.
The second half of the ride goes inland to Hōryū-ji, in Nara prefecture, which has the oldest wooden buildings in the world, dating from the seventh century. The two sites together tell the story of how early Japan buried its rulers and then built temples for its faith. Choose a spring or autumn morning, before the heat and the haze, and bring patience for the slow pace of local roads. Takaishi, to the south, is a quieter town with a pleasant coastline and good places to eat grilled fish.