This morning we purchased 3-day London Passes which would allow us to visit heaps of attractions for no additional charge. We had our first ride on the underground from Embankment (which is just around the corner from Citadines) to Tower Hill. From there it was a short walk down to the Tower of London which was so big and fascinating that we spent most of the day there. We also tried to visit London Zoo by taking the tube to Baker Street and walking the rest of the way. However, it was further than we realised and by the time we got there, the Zoo was closed.