Half Moon Passage, London E1

Looking south, with Alie Street just visible through the end of the passage. When they built this house, which I guess is late Georgian or early Victorian, they retained the alleyway by building a passage through the building.

These passageways and alleys have been preserved as public rights of way for centuries. At street level even the imperial stone and corporate concrete/glass buildings of the City often have passages and "courts" (courtyards), with the footprint of the building having been carefully constructed around what is essentially a medieval street-plan.