Heres a model of London in the Civil War times, in Spitalfields Market. It's actually a work of art, details here - http://www.craftpegg.com/page16.html
A wee model showing the area round City Hall and Potters Fields Park.
All the important bits of London modelled on a Camden shop
A London street in relief on a building down the Strand.
Roman London in the Museum of London.
And Legoland
And some more.
And in the V & A.
And in the Transport Museum.
And the London Museum at Docklands.