The Romans built their northern frontier along the Rhine, and in what is now the Netherlands they built a road beside it, running on the natural levee of the river, which was the highest and driest ground. Today the Kromme Rijn, the Crooked Rhine, flows past Utrecht as a small, quiet river, but in the first century it was the main channel, and the road ran alongside it, linking forts and watchtowers from the sea to the Roman towns upstream. At Utrecht there was a fort, Traiectum, from which the city takes its name, and nearby at Vechten stood the larger fort of Fectio, one of the most important along the Dutch stretch of the frontier.
De Balije lies in the Utrecht district of Leidsche Rijn, on the western side of the city, and I should say that what remains above ground is slight, and the road is mostly a line under the modern streets and fields. The modern district is a vast new suburb built since the 1990s, with the Roman past commemorated by markers and a small museum. Archaeologists found the old road, a ship and parts of a bridge here, preserved in the wet soil.
Riding in and around Utrecht is easy but unexciting. Roads are flat and well kept, and the dike roads along the Kromme Rijn and the Vecht are charming, with old farmhouses, country estates and blossom in spring. The city has an extensive network of cycle paths, and cars are limited in the centre. Speeds are low, and cameras are everywhere. The wind blows steadily across the polders, and in winter, fog sits on the meadows.
Veldhuizen is a suburb with shops and cafes, and Utrecht proper has fuel, restaurants and the great Dom tower, the tallest church tower in the country, visible from miles away. The area is known for its castles and country houses, such as De Haar. Try a pannenkoek or a bowl of pea soup in winter. Come in May, with meadows green and long light on the water.