The Cambridge Union Society on Round Church Street is the university's main debating society, operating since 1815 and a stepping stone for many who later entered politics, law, or public life. The grand Victorian chamber is still used for formal debates every term, with outside speakers ranging from Prime Ministers to comedians.
Guest debates are open to non-members who purchase visitor tickets. The society's library, housed in the same building, has an impressive collection of historical documents. The building itself is a mid-Victorian classical design — ornate by Cambridge standards. Check the programme at cus.org.