View of the road bridge Blackfriars Bridge and the covered railway bridge Blackfriars Railway Bridge in London. Blackfriars Bridge is a road bridge over the River Thames in London. It connects the City of London on the north side with the borough of Southwark in the London Borough of Southwark in the south. The bridge, which was build in Venetian-style, belongs to Bridge House Estates, a charitable organization of the Corporation of London and was designed by the architect and engineer Robert Mylne and opened in 1769. The associated railway bridge was designed by the architect John Cubitt and opened in 1864