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.
A great walk down an old abandoned rail way from Finsbury Park to Highgate. Most of the original platforms are sill remaining so its an interesting place to explore...
Beautiful museum with permanent collections on anthropology, natural history and musical instruments. Surrounded by a park with farm animals and beautiful views of London skyline.
Need some clean air or just a time-out? Kew Gardens is a short train ride away from the city centre but is provides you with space, greenery and and a small holiday for the lungs. The garden contain tropical glasshouses and interesting architecture, so it is a treat for both body and mind.