The church of All Hallows stood on the corner of Lombard Street and Gracechurch street as you can see on the parish map below. It was most commonly known as All Hallows Lombard Street but sometimes All Hallows Gracechurch because of its position. It was a simple church of Saxon origin but the first written record of the church is in 1054. Sometime around 1515 the church was rebuilt in stone and it inherited the bells of the monastery of St John in Clerkenwell when that institution was dissolved in 1544. The copperplate map of 1555 shows what the church looked like at that time (see below) .
When the Great Fire of London in 1666 caused significant damage, the parishioners tried to patch the building up. However, their repairs were rather shoddy and a completely new church was built by Christopher Wren in 1694. It was still fairly plain with a single, open, undivided space and no aisles. It was also so surrounded by other buildings as to almost be invisible.
The Demolition of All Hallows Lombard Street
By the 19th century, the commerce and trade of the Empire had driven the residential population out of the City to other parts of London. That meant there were far too many churches and not enough parishioners to fill them. All Hallows Lombard Street was deemed surplus to requirements and it was demolished in 1937. Parts of the church were reused at All Hallows Twickenham. In the photo below Wren’s stone tower stands incongruously next to the brick walls of the modern church. The only remains of All Hallows around Lombard street are the parish markers fixed high on the walls of the surrounding buildings. The photos show you where to find them.
The wikipedia page for All Hallows Lombard Street is here