And the answer: London.
Beginning in the Cotswolds on the outskirts of London, the River Thames runs through the heart of the city at London Bridge. From there, it ends at Southend in Essex and flows into the North Sea. The River Thames is 215 miles long (346 km) which makes it the longest river entirely in England and the second-longest in the U.K.
Once declared a "biologically dead" river, the Thames has made a spectacular comeback in recent years. Thanks to the advocacy of biologists and conservationists, as well as the advancement of modern septic technologies, the river is cleaner than it has been in 60 years. Today, about 125 species of fish thrive in the Thames— anything from European eels to seahorses make a home in its waters.
The Thames has taken on different meanings for Londoners over the years, yet has served as a center piece in the capital city throughout. For example, between 1608 and 1814, the waters of the Thames would freeze, allowing the annual Frost Fair to take place on the ice. Stalls selling food and drinks as well as activities such as dancing and ice skating were all made possible by the frozen river. On one occasion, an elephant was even led across the Thames!
The Thames has also historically hosted the oldest boat race in the world: the race for Doggett's Coat and Badge. This rowing competition is rowed over 4 miles and 7 furlongs (7400 meters) on the course chosen by Sir Thomas Doggett in 1715. The types of boat used for the race have varied over the years, (from four-seater passenger wherries to wooden racing boats), but since 2015, race sponsor WinTech Racing has provided new single sculls for all competitors’ use. The winner of the competition enjoys a host of perks often entailing long careers on the water, racing for Great Britain, or even ceremonial duties for the Royal Family.
Learn more about the history of the Thames river here.