Postman's Park opened in 1880 on the site of the former churchyard and burial ground of St Botolph's Aldersgate Church. The church is on the right here.
Postman's Park acquired its name due to its popularity as a lunchtime garden with workers from the nearby old General Post Office. It is home to the famous 'Memorial to Heroic Self Sacrifice', built in 1900 by Victorian painter and philanthropist G.F. Watts (1817-1904) - see Link (Archive Link ) The memorial is seen in the distance.
A tablet to Watts is part of the memorial - see Link
The complete Wikipedia entry for Postman's Park and the Memorial to Heroic Self Sacrifice can be seen at Link
These sculptures, above the portico of the Bank of England, were the work of Sir Charles Wheeler - part of a set depicting 'Creators and Guardians of Wealth' - for Sir Herbert Baker's reconstruction of the Bank edifice between the World Wars.