Laurence can be found in the vaults beneath St. Paul's Cathedral. In the altar space above is a memorial to John Donne, poet and Dean of the Cathedral in the 1620's, as well as a lovely Henry Moore Mother and Child.
Not far from the Tower of London is a sundial surrounded by a pictorial history of London transportation, including this one which I took to be Boadicea in her chariot.
From the Wiki: The Horse Armoury, located on the tower's north side ... was built in 1825. From its northeast corner, a wooden staircase ornamented with two carvings titled "Gin" and "Beer" ascended to Queen Elizabeth's Armoury. Gin and Beer represent the two most important alcoholic beverages of their time.
Tradition holds that if the Tower of London ravens are lost or fly away, the Crown will fall and Britain with it.