All Hallows-by-the-Tower, also previously dedicated to St. Mary the Virgin and sometimes known as All Hallows Barking, is an ancient Anglican church on Byward Street in the City of London, overlooking the Tower of London. Founded in 675, it is the oldest church in London, and contains inside a 7th-century Saxon arch with recycled Roman tiles, the oldest surviving piece of church fabric in the city. The Wikipedia page is [1] nd the website is [2].