Alma mater of six prime ministers, three saints and Douglas Adams (author of The Hitchhiker's Guide to the Galaxy), St John's is superbly photogenic. Founded in 1511 by Henry VII's mother, Margaret Beaufort, it sprawls along both riverbanks, joined by the Bridge of Sighs, a masterpiece of stone tracery and a focus for student pranks. Going into the college or taking a punting tour are the only ways to get a clear view of the structure.
Over the bridge is the 19th-century New Court, an extravagant neo-Gothic creation, and out to the left are impressive views of the Backs. Parts of the college are much older and the chapel, though smaller than King's, is one of Cambridge's hidden gems.
St John's is the second-biggest college after Trinity.