As a keen runner, running through Greenwich Park and on to the river side I see the Thames Barrier, which is not only the worlds second-largest movable flood barrier (after the Oosterscheldekering in the Netherlands) but is also an iconic site on what is fast becoming a recognised stretch for developers including the 02 and Ravensbourne College of Design and Communication.
Just above the Dorfman Theatre lobby at the National Theatre, is the entrance to the high-level walkway, a public walkway that overlooks the National Theatre props and scenic workshop.
It's free and is a unique chance to get a glimpse of what happens backstage. I love popping in when I'm on the south bank, as you get a completely different sight each time, depending on which production the workshops are working on at the time.