Emperor Ojin's tomb is the largest in Japan by volume, even if the Nintoku tomb near Sakai is longer, and it feels it. The mound is some four hundred metres long, a keyhole of earth with a double moat that holds water the colour of old jade, and the whole thing is so overgrown it reads from a distance as a wooded hill dropped into a town. Only the imperial household agency decides who sets foot on the mound, which means nobody does. What you get is a path around the outside, a worship platform at the front, and a very particular kind of silence.
It is called Konda Gobyoyama locally, and it sits in the Furuichi group in the eastern part of Osaka prefecture, close to Habikino. The ride labels it by the nearest bigger town, Kashihara, but the real setting is the Kawachi plain at the foot of the Kongo and Katsuragi range, flat, suburban, busy with commuters. There are no wide open roads here, just short hops between traffic lights, but it all happens quickly and fuel is everywhere.
What makes the place special is scale. To grasp it, walk the perimeter path; the walk is long, and the curved wall of trees on your left never seems to end. The moat attracts herons, and in winter ducks gather in the water. Early morning is best, with the low sun flat on the ground and joggers drifting past.
The tomb dates to about the late fourth or early fifth century and belongs to the age when the Yamato rulers had the technology, the labour and the ambition to move thousands of tonnes of earth for a funeral. Archaeologists have found clay haniwa figures, bits of armour and horse gear, and the cluster around it includes dozens of smaller tombs for relatives. Many are tucked behind ordinary houses.
Go in spring when the cherry trees line the nearby lanes or in the gold of November. In summer the heat in this basin is sticky and heavy, and a canned coffee from a vending machine becomes a ritual.