Nonnebakken is a modest mound in the suburbs of Odense, easy to miss and worth finding. In the late tenth century, in the time of Harald Bluetooth, the Danish king ordered the building of a group of circular fortresses, each laid out with a ring rampart and gates facing the four directions, and the one at Nonnebakken is the Funen member of that family. Its name means the nuns' hill, which probably refers to a later medieval convent on the spot, and the earthwork lies in a residential area, so you will be walking among houses, gardens and quiet streets rather than open countryside.
The site was excavated in the 1950s, and archaeologists found the outline of the fortress, together with the post holes of houses laid out in a precise pattern. Like Fyrkat in Jutland and Trelleborg on Zealand, the fortress belongs to a period when the Danish kingdom was consolidating its power and converting to Christianity, which is why the nearby Jelling mounds, with the runestones that Harald raised, form part of the same story. There is not a great deal to see on the ground, because the original timber structures have long gone, but information boards and the shape of the ground tell the tale if you slow down.
For a rider, Funen is a good place to be. The island is Denmark's garden, with orchards, farms and thatched villages, and the roads are smooth, narrow and well maintained. Corners are gentle, with the surprise of a hill now and then, and the sea is never far away, so every few kilometres brings a view across a fjord or a bay. Enforcement of speed limits is strict. The big Great Belt Bridge, a toll crossing, lies to the east and links Funen to Zealand, and the Little Belt Bridge links it to Jutland.
Odense, with about a hundred and forty-six thousand inhabitants, is a proper city, so fuel and food are not a worry. Seden and Neder Holluf are suburbs with supermarkets and stations. The best time to visit the mound is in the morning when the city is quiet and the grass is wet with dew. In spring the local gardens are full of blossom, and in summer the long evening light lasts until almost eleven. It is a small place, but it connects you to a large story.