Some two thousand years ago, in the year 47, the Roman general Gnaeus Domitius Corbulo had a canal dug between the Old Rhine and the Maas to give his ships a safe route behind the dunes and avoid the dangerous coastal sea. Tacitus mentions it, and later sources say that Corbulo, recalled by the emperor Claudius from further conquests in Germania, kept his soldiers busy with the digging rather than let them grow idle. The channel is known as the Fossa Corbulonis, and in today's landscape it is usually identified with the Vliet, the old waterway that runs between Leiden and Delft through Voorburg.
Voorburg, which is part of the Hague region, was Forum Hadriani, a Roman town named after the emperor Hadrian and the only Roman town of that status in this part of the Netherlands. The marks it left are modest: a few remains, a museum and a signposted Roman Path that runs along the waterside. But as part of the Lower Germanic Limes, the Rhine frontier of the empire, the area holds the memory of one of the largest frontiers the Romans ever built.
On a bike, this is flat, built-up country, and the interest is more in the quiet backroads than in drama. The Vliet is lined with old villas, small bridges, rowing clubs and weeping willows, and the roads along the water are narrow, brick-paved in places, and shared with many cyclists, who have priority in their own way. Traffic around The Hague is dense, trams complicate junctions, and parking is expensive, so a short walk is better than a long ride here. Spring blossom and autumn mist add atmosphere; winter brings grey skies and wet cobbles that deserve respect.
Voorburg has thirty-eight thousand people and a full supply of fuel, shops, bakeries and cafes; the Hague is on the doorstep. Herring and raw onion at a fish stall is the classic local snack. Amsterdam and the canal ring, which is the destination of the ride, lie about fifty kilometres to the north, where the seventeenth-century merchants made their own engineering marvel, a ring of canals that is arguably the more famous descendant of the Romans' modest ditch.