The Mathematical Bridge is the wooden footbridge over the River Cam at Queens' College, Cambridge, just north of Silver Street. It looks curved, but it is built entirely from straight timbers, arranged so that together they work like an arch. And despite the story told on every passing punt, Isaac Newton had nothing to do with it.
The Mathematical Bridge at a glance
- Where: Queens' College, over the River Cam, best seen from Silver Street bridge.
- Built: 1749; repaired in 1866 and rebuilt to the same design in 1905.
- By: designed by William Etheridge and built by James Essex the Younger.
- What it is today: a footbridge inside a working college, linking the college buildings on the two banks of the river. It is private property, so most visitors see it from the street or the water.
- Time needed: 10 minutes from Silver Street, longer if you visit Queens' College.
Straight timbers, a curved bridge
Queens' College was founded in 1448 by Margaret of Anjou, wife of Henry VI, and refounded in 1465 by Elizabeth Woodville, wife of Edward IV, which is why the apostrophe comes after the s. By the 18th century the college stood on both banks of the Cam. William Etheridge designed the bridge in 1748 using a system of trussing he had learned from the carpenter James King, and James Essex the Younger built it in the summer of 1749. The trick is in the geometry: the main timbers are tangents to an imaginary circle and carry the load mostly in compression, like the stones of an arch, while radial timbers tie them into rigid triangles.
Wood rots, and the bridge has been replaced more than once. In 1866 decayed cross-beams were repaired and the stepped deck was changed into the slope you see today. In 1905 the bridge was rebuilt by William Sindall to Etheridge's design, this time in teak. The bridge has never had an official name: in the late 18th century the college called it Essex's Bridge, and guidebooks were calling it the Mathematical Bridge by 1803. Essex had also built a similar bridge at Garret Hostel Lane, and when that one was replaced, the nickname seems to have stayed with the bridge at Queens'.
What to look for
- The straight timbers: there is not a single curved member in the arch. The curve you see is made by the tangent beams meeting at shallow angles.
- The radial timbers, pointing towards the centre of the imaginary circle and locking the tangents into triangles.
- The bolts: since 1905, coach bolts pass through each joint, with the nuts on the outer faces and the bolt heads on the inner faces.
- The sloping deck, which replaced the original steps in 1866.
- The riverside building behind the bridge on the east bank, dating from around 1460, which contains parts of the President's Lodge.
The Newton myth
The story goes that Isaac Newton built the bridge without a single nail or bolt, and that curious students or fellows later took it apart to see how it worked and could not put it back together without bolts. It is a legend and nothing more. Newton died in 1727, twenty-two years before the bridge was built, and no record links him to it. The bridge has also always had fixings at its joints; before 1905 they were simply less visible.
Tips for your visit
- The best view is free: stand on Silver Street bridge and look north along the river. Morning light on the timbers is softest.
- See it from the water: punts heading for the Backs pass right under it, and the angle from below shows the triangles clearly.
- Queens' College is a working community and closes to visitors at some times of year, especially around exams. Check before you plan to go inside, and keep off areas marked private.
Nearby
- The Backs: the lawns and gardens behind the colleges along the Cam, best seen on foot or from a punt.
- King's College Chapel: the late-Gothic chapel with its fan-vaulted ceiling, a short walk north.
- The Corpus Clock: the gold clock topped by a metal creature that seems to eat time, unveiled in 2008 on the corner of Bene't Street and Trumpington Street.
- The Fitzwilliam Museum: the university's museum of art and antiquities on Trumpington Street, with Egyptian finds, paintings and much more.
See Cambridge with World City Trail
Our Cambridge scavenger hunt turns the old town into a game you play on your phone. The route links 10 stops and takes around 3 hours, with about 35 minutes of walking. Along the way you visit places such as Parker's Piece and the Scott Polar Research Institute. You can play in English, German, French, Italian, Spanish and Dutch.
If you prefer a different format, there is also a self-guided walking tour and an outdoor escape game in Cambridge.
Play the Cambridge scavenger hunt →
Take the self-guided walking tour of Cambridge →
Play the outdoor escape game in Cambridge →
Facts checked in October 2026.