A straight line on a Dutch map is nearly always a canal, and this one is two thousand years old. The Fossa Corbulonis, or Corbulo's canal, was dug in AD 47 by Roman soldiers under the general Gnaeus Domitius Corbulo, to link the Rhine with the Meuse and give supply ships a safe route that avoided the open sea. It ran through the dunes and marsh of what is now South Holland, and today the line of the Vliet, the canal between Leiden and Delft, follows part of it. Corbulo, so the story goes, dug it to keep his idle legions busy, and the emperor Claudius called his troops back from beyond the Rhine soon afterwards. Vlietvoorde, near Voorschoten, is one of the places where the route can be traced, and the site is part of the Lower German Limes, which won World Heritage status in 2021.
The landscape here is the classic Dutch polder: flat fields below sea level, drained by ditches, with cows, windmills, rows of poplars and red-tiled farmhouses reflected in the water. The sky does most of the work, with huge clouds sailing across, and the light is clear and soft. Leiden, the university town, is a few kilometres to the north, and the Hague to the south, while the dunes and North Sea beaches lie a short ride west. In April and early May, the bulb fields around Lisse bloom in long stripes of colour.
The ride goes on to the Dutch Water Defence Lines, the system of flooded fields and forts that protected Holland for centuries by letting the water in, and it is a gentle journey over dikes and along canals. The roads are narrow, often with a cycle lane, and the speed limit is low, usually eighty on the open road and fifty or thirty in villages, with cameras and police who enforce it. Cyclists are everywhere, so patience is a virtue, and the wind, often from the west, can be a nuisance on the open stretches.
Voorschoten, a small town of about twenty thousand, has fuel stations, a few cafes by the canal and a pleasant old centre. Dutch food is simple: herring with onions at a market stall, cheese from Gouda, and thick pancakes. The best months are May, June and September, when the days are long and the light is golden. If rain comes, as it does, a good waterproof will save the day.