River Thames
In the 17th and 18th century, at a time some call the "Little Ice Age", the Thames often froze over in the winter. This led to the first "Frost Fair" in 1607, with a tent city set up on the river with lots of odd amusements, like ice bowling. The last time the river froze over was in 1814. The building of a new London Bridge in 1825 may have helped stop it from freezing: the new bridge had fewer pillars than the old, allowing the river to flow more easily, and stopping it from flowing slowly enough to freeze in cold winters.