A heron stands in the moat as if it has been paid to be there. That is the first thing worth knowing about Magodayuyama: like most of the large burial mounds of Sakai, it is surrounded by water, and the water is full of life. Carp, turtles, reeds and a surprising amount of birdsong turn up in a part of Japan that otherwise has plenty of concrete. The mound itself is covered in trees that nobody has felled for centuries, since the Imperial Household Agency looks after many of these tombs and keeps people off them. You walk around the edge, not over it, and you read the shape from the lie of the moat.
These tombs belong to a cluster of fifth-century monuments around Sakai that earned World Heritage status in 2019, a few dozen mounds built when the rulers of Yamato were growing strong and wanted the ocean traffic from Korea and China to see how strong. The biggest, the Daisen Kofun, is nearly half a kilometre long. Magodayuyama is the quiet cousin, handy and unpretentious, tucked among houses, which is just the kind of place where you learn how Japanese towns absorb enormous history without a fuss.
The ride that starts here points inland and then up. Yoshino and the Omine mountains mean cedar forest, tight lanes and shadows, with Ominesan-ji, the temple of the mountain priests, beyond the hot-spring hamlet of Dorogawa. Reaching that area from Sakai usually means working through Nara prefecture, and the road gets narrower and slower the higher you go. In places a car and a motorbike must negotiate who gives way, and the surface can be damp and covered in needles and leaves. Treat it with respect, and go earlier rather than later in the day, because the valleys lose the sun quickly and the temperature drops by the kilometre.
For fuel, take no chances. Sakai has stations on every corner, and the next real choice is down in the valley towns on the Nara side. Dorogawa has onsen and a handful of simple places for noodles, but do not count on anything being open outside the main seasons. Spring brings cherry blossom up the Yoshino slopes in stages, from the foot to the summit across several weeks, and autumn is clear and calm. Midsummer is steamy, and typhoon season, in September especially, can close mountain roads for days.