London's skyline is constantly changing. Construction cranes pepper the horizon and new skyscrapers shoot up at a dizzying rate. Just as Londoners get used to one unusually-shaped steel and glass tower on the City skyline, another muscles in on the view.

There is the Gherkin, the Walkie Talkie, the Cheesegrater and – coming soon – the tallest of them all: 1 Undershaft but, amid all the change, there seems to be one constant: the 47 churches in the Square Mile, as the City of London is known. Temples of Mammon go up and come down and go up again, but Sir Christopher Wren's places of worship stand their ground.

Reuters photographer Toby Melville loves finding creative ways to capture these historic survivors. He says: "A spire or church tower, once prominent, may now be swallowed up or hidden. But look hard – it's still there down a street or alley, emerging between the glass and steel."

In the 16th century, there were 111 churches in the City. Eighty of them were destroyed by the Great Fire of London of 1666, and 51 were rebuilt under the direction of Sir Christopher Wren with backing from King Charles II.

In the Victorian period, congregations shrank as people moved out to London's new suburbs. More than a dozen churches were replaced by buildings devoted to commerce, not worship.

Nearly all of the City's churches were damaged by German bombing during the Second World War and rebuilt to Wren's designs. Only a handful of Wren's masterpieces survived the Blitz, most famously St Paul's Cathedral. Views of the cathedral are protected from various locations around the city, leading architects to come up with creative designs for skyscrapers, such as 122 Leadenhall Street, known as the Cheesegrater because of its wedge shape.

Developers would love to get their hands on these prime locations. Voluntary organisations fight to keep the City's centres of worship alive today. They try to widen their appeal by staying open all day and offering on-site cafes, lunchtime concerts and recitals to entice City workers, passers-by and tourists.

Melville says: "For some, these buildings provide respite from the bustling life of big business, an antidote to the frenzied pace of modern life. For others, it's a place to eat a sandwich, sit and pause for thought, or enjoy buildings and artefacts from a different era. Amen to that."