It's a bucket list item. St Paul's Cathedral. The whispering gallery is here.
Buckingham Palace Changing the Guard
Beautiful Big Ben
Downing St where the PM lives at No 10.
The First Shop in the World is so called because it is only Zero degrees, zero minutes, and just 24 seconds from the Zero Degree Meridian line. This line, of course, is in Greenwich. Thus Greenwich Mean Time.
Maritime College Greenwich.
Tristan astride the Zero Degree line thus placing himself both in the East and the West.