Useful links
free London Transport Maps
interactive Underground map
Writers Walk
From the British Museum, follow this walk to see Great Ormond Street Hospital, Bloomsbury and Senate House
The Nautical Walk
From the National Maritime Museum, explore the world heritage listed town of Greenwich
There are lots of fun and interesting indoor things to do in London.
Everything from visiting one of the many wonderful museums and galleries to spending an afternoon in one of the various historic London pubs.
And many of the markets have large covered sections, so there's always something to do in London for free even when the weather isn't brilliant.