The Cambridge College Backs: every college and bridge you punt past

What are the College Backs?

The Backs are the stretch of the River Cam that runs behind a line of the old Cambridge colleges, where their lawns, gardens and grand stone buildings come right down to the water. It is the view Cambridge is famous for, and a guided punt is the only way to see all of it in one go.

On foot you catch the colleges from the front, off the busy streets. From a punt you see the side almost nobody photographs from anywhere else: the back lawns, the chapel rising over the river, the bridges that link one bank of a college to the other. The word Backs simply means the backs of the colleges, and the green open land behind them along the Cam.

A standard chauffeured tour covers the core run in about 45 to 50 minutes, there and back, with the guide poling and telling the stories while you sit and look up. You do not need to steer, balance or paddle. For how that tour actually feels and what to expect on the day, see our shared punting tour page.

The route in order: college by college, bridge by bridge

Most guided punts work the Backs from south to north, starting near Queens' College and turning around past St John's. In order you pass Queens' College and the Mathematical Bridge, King's College and its chapel, Clare College and Clare Bridge, Trinity Hall, Trinity College, then St John's College and the Bridge of Sighs.

Tours run from different stations, so your exact start point and direction can vary, but the cast of colleges and bridges is the same. Here is the core run and what to look for at each college.

Colleges in the order a typical south-to-north Backs tour passes them. Your station and direction may shift the start point.

The first stretch is the busy, postcard part: Queens', King's and Clare follow each other quickly, so the famous shots come early. By the time you reach Trinity and St John's the river usually opens up a little, and the bridges do the talking.

The famous bridges: the Mathematical Bridge, Bridge of Sighs and Clare Bridge

Three bridges get asked about more than all the others put together: the Mathematical Bridge at Queens', the Bridge of Sighs at St John's, and Clare Bridge, the oldest of the lot. They are the moments most people remember from the water.

The Mathematical Bridge is the wooden footbridge at Queens', built in 1749 to a design by William Etheridge. The famous legend says Isaac Newton built it without a single nail, that students later took it apart to study it, and that they could not put it back together, so they had to add bolts. It is a good story and it is not true: Newton died in 1727, well before the bridge existed, and it has always used fixings. The clever part is real though, the way the straight timbers are arranged so the load runs along them in a curve.

The Bridge of Sighs at St John's is the covered stone bridge built in 1831 that crosses the Cam to join two of the college's courts. It takes its nickname from the Venetian bridge it loosely recalls, and Queen Victoria is said to have loved it. From a punt you glide almost underneath it, which is the angle that makes the photo.

Clare Bridge, built in 1639 and 1640, is the oldest surviving bridge on the Backs. It is a low three-arched stone bridge topped with decorative stone balls, one of which famously has a wedge cut out of it, with several stories told about why. Quieter than the other two, it is often the prettiest in soft light.

A College Backs run passes around nine bridges in total; these are the ones visitors ask about most.

Best views and photo spots from the water

The best shots on the Backs are the ones you can only get from a punt: King's College Chapel framed over the back lawn, the underside of the Bridge of Sighs, and the wooden curve of the Mathematical Bridge low against the water. A good guide times the route so they land in decent light.

The single most-wanted photo is King's College Chapel from the river. From the bank you fight crowds and railings; from the water the chapel sits clean above the green lawn with nothing in front of it. Have your camera ready before you reach it, because the punt does not stop.

For the Bridge of Sighs, the trick is the approach: shoot it as you glide toward and then under it, not after, when you are looking back at its plain side. The Mathematical Bridge rewards a low angle, which is exactly what the punt gives you. Here is where to be ready on each stretch.

Highlights by stretch, in the order a south-to-north tour reaches them.

When to go for the quietest, prettiest Backs

Go early. The Backs are quietest in the early morning, with soft light, far fewer punts on the water and room to actually take in each college. They are busiest midday in summer and on weekends, when the river fills with traffic.

Punting runs year-round in Cambridge except Christmas Day, but the season people mean is roughly spring to autumn. Late spring and early autumn are the sweet spot: good weather, longer light, and a calmer river than peak summer. If you can only go in summer, the first departures of the day and the late afternoon are far better than the midday crush.

Light matters as much as crowds on the Backs. Early and late, the low sun warms the stone and throws the bridges into relief, which is when Clare Bridge and the chapel look their best. For a full month-by-month read on weather, crowds and the calmest times, see our guide to the best time of year to punt.