Concrete has a way of outlasting the fear that poured it. Type P group shelters belong to the Dutch defences of the late 1930s, small low bunkers designed to give a section of soldiers somewhere to sit out shelling while they waited for an attack. This one is on the eastern fringe of Utrecht, beside the university quarter of De Uithof, in a belt of land that was meant to be flooded rather than fought over.
The idea behind the Waterline was simple and a little unnerving. Open the sluices, let the fields fill to knee depth, and an advancing army finds roads submerged, ditches hidden and boats unable to float. Forts and shelters stood on the dry spots to cover the approaches. In practice, in May 1940 the line was not tested in the way its planners hoped, since the Dutch army capitulated after the bombing of Rotterdam and the German advance was fast; but the shelters are still here, mossy and strangely small, grass growing on their roofs.
Getting to them by motorcycle is easy and slightly comic. You leave the busy ring and the clatter of the university, then slip along lanes where bicycles outnumber cars twenty to one, past pollarded willows, drainage ditches and the odd riding school. Keep your speed polite. The cycle lanes are painted red, the surfaces are good, and the Dutch signs mean what they say. Windy days off the polder are common; autumn mornings often bring ground fog that hangs low over the fields until nine or ten.
Fuel is no trouble, because Utrecht lies just next door with stations on the ring road, and a city of this size has coffee in every direction. The Oudegracht is the place for a proper stop, with its sunken wharves and cafés tucked in under the arches, and the Dom Tower, rising 112 metres, is a pleasant landmark to steer by. Most bunkers in this area are fenced or locked, so take photographs from the path and leave them be.
The best moment is a dry weekday evening in late summer, when the light is low and gold on the grass and the last students have gone home.