Take a tube to Picadilly Circus, walk from there to Leicester Square, take few steps back and take Whitcomb Street next to Swiss Centre into China Town, then cross Shaftsbury Avenue and through "Red Light Disctrict" to Berwick Street market in Soho, then to Oxford Street. Turn right on Oxford Street and follow it to Center Point. Turn left into Tottenham Court Road when you see big statue of Freddy Mercury with "We Will Rock You" banner then take first right by YMCA building into Great Russell Street. Go two blocks to British Museum, entry is free, choose your tour wisely as it's impossible to see everything in one day and most of displays are made into maze of small corridors rather than big loop, so you'll find yourself going back and forwards through the same displays. When you had enough, take Coptic Street out of the museum, back to Shaftsbury Avenue, cross High Holborn and turn into Neal Street. Follow it to Covent Garden, exit the market via Southampton Street onto The Strand, turn right and follow The Strand all the way to Trafalgar Square. From there you have two choices, depending on time left - either turn left to Whitehall to check out horse guards, Big Ben and Parliament Square or turn right, walk back to Leicester Square and take a tube home. The whole trip is only about 3.2 miles long but you get to see most of the inner city tourist attractions on your way.