Saint Dunstan-in-the-East was first built in 1100.
It was badly damaged in The Great Fire and then repaired, rather than being rebuilt, in the late 1660s. The Wren steeple being added in the 1690s.
The church was severely damaged in The Blitz and was not rebuilt. The ruins were eventually opened as a public garden in 1971.
More information can be found on Wikipedia.