A heatwave made the Thames smell so foul that Parliament fled the building

By the summer of 1858, London was dumping raw sewage straight into the Thames, and an unusually hot July baked it into a stench so overpowering that MPs reportedly held handkerchiefs to their faces in session and some committees relocated. The 'Great Stink' finally forced Parliament to fund Joseph Bazalgette's sweeping new sewer network, which is still part of London's drainage system today.

— Stephen Halliday, The Great Stink — The Great Stink of London, Sutton Publishing, 1999