A must see for all tourists. Get off at Westminster tube, have a look at parliament (Big Ben) and then walk past No.10 on the way. It's a very nice walk.
Transport: St James's Park, Victoria, Green Park (underground rail)
Phone: (020) 7766 7324
Hours: 09:30-16:30 28 Jul-25 Sep, timed ticket with admission every 15min website