Not been in many years, but spent a large part of my childhood watching people row and sail back and forth. It freezes over in winter and in February 1893, Jack Selby drove a coach and four horses across the reservoir.
Eccentric and surprising house and museum of architect Sir John Soane. Mostly unchanged since his death over 180 years ago, it is full of atmosphere. Also have spotlit, late night openings.
These giant spectral cylinders are great at different times of the day but my favourite time is around dusk when the buildings in the city start to light up. The Gherkin and the new Shard building are framed in the lowest ring then the shifting colours of the sky are almost split in the following ellipses.