A Roman fort is a surprising thing to find in a Dutch village, but Valkenburg has one buried underneath it, and the old Rhine still runs past its doorstep. The centre of the village is a small cluster of houses, a church and a few shops around a bend of the Oude Rijn, a few kilometres from the dunes of the North Sea coast. Roman soldiers built a fort here, Praetorium Agrippinae, to guard the river frontier of the empire, and the site is part of the Lower German Limes, which is now a UNESCO World Heritage property.
Little of it is visible, because the Dutch landscape swallows its past quickly, and you need a little imagination. Still, the street plan and the river line help, and an information panel or museum visit in the area can fill in some detail. Archaeologists connect the first fort here with the reign of Caligula and his abandoned plan to invade Britain, which gives a sleepy Dutch village an unlikely place in imperial gossip.
On a motorcycle the village is gentle and low-speed, with narrow streets, speed bumps and a tide of bicycles. The surroundings are flat polder, and the roads that leave it follow canals and ditches, which means few real bends and plenty of straight sections with the sea wind pushing against you. Expect to share the road with cyclists, farm vehicles and, in spring, trucks carrying flowers from the bulb fields toward the auctions. The tulip season runs through April and early May, and the fields around Katwijk and Rijnsburg are lovely then, though riding along the narrow lanes in a crowd of tourists is less fun than it looks.
Fuel can be had in Rijnsburg or in the larger towns of Katwijk and Leiden, which are all within a few minutes. Coffee in the village is simple, and Katwijk has fish, beach and a wide promenade. If you have time, the university city of Leiden, with its canals and old botanical garden, is a proper place for lunch.
An early start on a quiet, clear morning shows the mist lifting off the river and the fields outlined in silver.