Cambridge is flat, and for a motorcyclist that is both its weakness and its secret. The city sits where the chalk of the Gog Magog hills runs out into the fens, and the River Cam wanders through its heart past the colleges, between lawns and willows, under little bridges where punts jostle on summer afternoons. King's College Chapel, begun in the fifteenth century and finished under the early Tudors, has a fan-vaulted ceiling that looks as if it were carved from lace, and its choir sings evensong most days of term. More than 158,000 people live here, so fuel, food and a bed are never in doubt.
The city is a very hard place to ride in the middle. Cyclists rule the narrow streets, bus gates and one-way systems cut across the centre, and parking for anything with an engine is scarce and expensive. Do the sensible thing: park at the edge, perhaps near one of the big park-and-ride sites, and walk in. The old courts and lanes are best seen on foot anyway, and the Backs, the lawns behind the colleges along the river, are impossible to see from a saddle.
Leave the city and the reward arrives. East and north, the land opens into the fens, a country drained from marsh by Dutch engineers in the seventeenth century, black-soiled and so level that the sky seems to take up three-quarters of the view. The roads here run dead straight along dykes and drains, and every so often take a sharp right angle for no reason except the line of an old ditch. Wind is the main hazard, and in winter, fog and frost. To the south-east the Gog Magog hills offer the only real climbing for miles, a gentle ridge of beech and chalk grassland.
For a start or finish, Cambridge has a very good rhythm. A morning coffee in a bakery, a quiet departure while the students are still asleep, and an evening return along the river, when the college windows light up one by one and the bells begin. It is a city of long memories, and a few of them linger in the way the evening light falls on the old stone.