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.
I love how much you are aware of the changing seasons out of the city; there are numerous beautiful forests around Hertfordshire to go for a run, a walk or have a picnic. One of the best destinations for a day out from London might be Northaw Great Wood. The main entrance is located on the Ridgeway, the B157 from Cuffley to Brookman's Park.