Gas Lamps and Penny Farthings
The first gas lighting appeared on Pall Mall in 1807 and began to spread from 1812 when the London and Westminster Gas Light and Coke Company was created. Early gas was created by heating coal which then released mainly hydrogen. More about present day London’s Gas Lamps and where to see them. The best place being the broad avenue of Kensington Palace Gardens. The gardens do close at dusk but there is information about turnstile exits here.
A more intense light could be created by directing an oxyhydrogen flame upon a cylinder of quicklime (calcium oxide). The resulting light was commonly known as limelight and used for stage lighting. Hence the term “being in the limelight” is used to mean being the center of attention.
These gas lamps are just outside the British Museum with a Penny Farthing bicycle further down the page.
British Museum
Sutton Hoo Treasure
Sutton Hoo Helmet

The replica helmet and mask are part of the Sutton Hoo Treasure (Wiki) with more at Sutton Hoo Site. The original find is further down together with more artifacts from antiquity.
The Museum
The British Museum (for details, admission and location) is probably the largest in the UK and contains artifacts from all over the world, from antiquity to more recent times. Whilst there is some controversy about ownership of some items (e.g. the Elgin Marbles), the museum has preserved what otherwise might have been lost and is free to all visitors. There is a an extensive cloakroom and non-commercial photography is allowed.
Of similar interest is the Victoria and Albert Museum, which is dedicated to design from across the world. More from the British Museum:-
Cosy
Nefer Teapot Nefer did
Rar
Raaaar
Moo see um