I love London but sometimes it's nice to surround yourself with trees and calm. Kew Gardens is a little bit of paradise in London.
It does cost a bit to get in and they charge you more on the door so try to pre-book your tickets. Currently it's £16.50 on the door but £14 if bought before. but they really do make it worth it when you're in.
It is full of West-London mummies and children but equally, it's the kind of place you could take your Grandma who will love The Orangery, where you can have afternoon tea and taking a walk around the conservatories.
The tree top walkway is incredible and there seems to always be some kind of festival or special event on. At the moment they have a spice festival running all summer which has some great little event activations.
They have some strange looking inflatables, one that is supposed to look like a garlic and one that is supposed to look like a nutmeg. They're not great to look at but what is clever is the little zip which lets you look inside and a fan pushes out the smell of each (the garlic or nutmeg) is intense, a very clever way to encourage you to go to one of the many cafes.
I find that taking myself back to nature and walking around somewhere like Kew is a great source of inspiration, it clears your head.