London was the capital of Roman Britain under the name of Londinium. The settlement was established on the modern day London around 43 AD. Its bridge over the Thames turned the city into an important port and the most powerful settlement of Roman Britain. The settlement was abandoned during the 5th century.
Today London is a huge modern city and capital of the UK. However, around and beneath London are the remains of its Roman past. Sections of the boundary wall to protect London remain, a Romano-Celtic temple was found and excavated at Gresham Street, beneath the Guildhall Art Gallery are the remains of an amphitheatre and occasionally Roman structures are incorporated into modern buildings so they can be viewed and studied later on, but most are not for public viewing.