Pre-requisite: Tourist in London 101
Because a visit of London is not complete without seeing the famous Tower Bridge, it is always worth it to folow the horde of tourists or the open roof tour buses that goes east.
I however recommend to visit thispart of town on foot as the sight is very unique.
For the lazy tourist like me, it is nice to start the walk at Tower Bridge itself. This is the bridge that opens and splits to let boats with high mast pass through. Walking along the south bank of the Thames, following a path called the Queen's Walk, it's always very strange to see the odd mix of modern and ancient architecture across the river. The Tower of London and the modern glass building the Gerkin very much symbolizes the timelessness of London.
The Tower of London has a Traitor's gate that opens on the river. I heard once that the last traitor whose head hung above it was none other than Braveheart (no no, not Mel Gibson!).
Further up the river, a huge naval ship is anchored and has been recycled as a naval museum. It can probably be rented as well for Christmas parties and New Year's Eve dinners. A note for the die hard window shopper: there are no clothes shops at all on this walk. There are however lots of galleries along the way that can tempt the big spenders.
The next sight is the Shakespeare Globe Theatre.
This is truly amazing as it was built with the materials they would find in the 16th century. 
There are no bolds, nails or anything in that whole building. Its all wooden knobs and big joints. The inside is amazing as well and watching a play in that theatre is sucha thrill (a few members of the audience faint) as the actors runs among the audience. The plays use 16th century sound effects and special effects (canons, nice gooeye red blood, pots and pans)and usually last 3h.
And of course, right next to this ancient architectural reproduction sits a red brick power plant. But instead of bringing the crowd some common electricity, it now hosts the Tate Modern, which is a free museum of modern and contemporary art, electrifying the public with its often strange exhibitions.
It is best to cross over to the north bank of the river at this point, using the millenium bridge. It's a pedestrian bridge that is quite slippery when it rains. Most importantly the view is beautiful from the south bank as it shows the dome of St Paul's cathedral in the background. You can either rest your feet inside the protective massive dome or start to roll down the hill along Fleet Street and end up in the West End where plays and musicals can be booked and enjoyed all year round (except Christmas, NOTHING is open on that day).This can be done in an afternoon or on a much slower pace to fill the day. Besides, when the weather is that sunny, there is no rush really. If you have fog, rain and cold weather though, maybe you can take a boat tour instead...or enjoy one of the museums....indeed, there is a museum in every post!
