This is hosted in Kenwood House which is a free entry if you ever find yourself in London on work or whatever. It is right on the edge of Hampstead Heath which

This is hosted in Kenwood House which is a free entry if you ever find yourself in London on work or whatever. It is right on the edge of Hampstead Heath which is some fairly large (~800 acres) and fairly wild heathland and forest that is a good place for long walks or running (quite hilly in places, great views (legally protected!) over London as a result), quite close to the center of London (~10-15 mins away from Kings Cross on the tube). Do check it out if you want some outdoor space or a good place for a run when visiting London