Not the most exciting place inside, but a lovely rooftop area which not all that many people seem to know about, 2 mins walk from Old St station. If it’s packed then The Red Lion is just up the road.
Free natural ponds, open all year round (check online for varying opening hours according to seasons). Get an absolute get away feeling right in the heart of London, a treat if you enjoy swimming with ducks. Amazing park to enjoy a few games of cards and a walk around afterward too...
London’s wildest and best park to get lost in. Just follow your instinct, chase trees, go up to the viewing points and you’ll always find breathing and mindspace in Hampstead Heath. If you can, visit often, as it goes through wonderful changes over the seasons.