I've travelled the world and its my favorite city. I know it well
Buy and Oyster card when you get there and you can top it up as you use it.
West Minster Abey
Tower of London
Walk the Mall from Trafalgar Square and see Green Park and St James Park the Buckingham Palace.
Grab a Beer at St Stephen's tavern across from Big Ben
Walk White Hall to Trafalger square and see 10 Downing and the Horses Guards, then walk St James park after seeing the Churchill War Rooms to Buckingham
Museum of Natural History
Imperial War Museum
Royal Air force Museum (100% must see) take the tube to Colindale Station
St Paul's Cathedral
Take in a Play in the Theater District.
I could go on and on.
Great city. TONS to see
Just to add to some of Ron's suggestions, although bear in mind it's over 20 years since I worked in London so may be out of date:
"Walk the Mall from Trafalgar Square and see Green Park and St James Park the Buckingham Palace." - You may wish to pause in remembrance at the Guards memorial.
Whitehall: plenty of pubs and bars if you fancy a buit of refreshement. The Red Lion in Parliament Square; the Old Shades; the Clarence; the Silver Cross; and round the corner in Northumberland Avenue, the Sherlock Holmes.
Covent Garden is well worth a visit. Also has the shortest stretch of tube line between two stations - Leicester Square to Covent Garden on the Picadilly line.
Endorse the museums: the Science and Natural History museums are well worth a visit, as is the RAF Museum. While there, it's a short walk to Hannants Colindale shop, but check opening times on their website.
If the Albert in Victoria Street is still there, they used to do a great breakfast.
There are plenty of sightseeing buses and river boat trips.
And noting where you're from, you may wish to go see the Earls Court Road, it's not that far from the Science & Natural History mueums iirc.
Whatever you decide to do, have a great time.
Edited by MikeC, 03 September 2017 - 06:37 AM.