The wonderful thing about this route is that it combines two of London’s must-visit areas; starting at Tower Bridge as well as the adjacent Tower of London, and ending in the royal borough of Greenwich, where tourists come from far to visit the National Maritime Museum, the Cutty Sark and Greenwich park.
I recommend getting there early to see the bridge open around 9am in the morning. Although I have not seen the lifting, this was recommended to me be commuters.
The cathedral stands on the highest point of the city and was completed in 1710. If you have time or are just dying to see the inside I recommend saving some time and money by purchasing a ticket online.