All Hallows by the Tower is the oldest church in the City of London. It predates the Tower of London by nearly three hundred years, and was founded in 675 AD. An arch from the original Saxon church remains. Beneath the arch is a Roman pavement, discovered in 1926, evidence of city life on this site for the best part of two thousand years. William Penn, founder of Pennsylvania, was baptised in the church and educated in the schoolroom (now the Parish Room). John Quincy Adams, sixth president of the USA, was married in All Hallows in 1797.