Leake Street Arches beneath waterloo station is a legal graffiti tunnel with constantly changing street art. Free 24/7 access via lower marsh entrance and interesting restaurants like master wei tucked in the railway arches. The vaults theatre hosts experimental performances here.

St Dunstan-in-the-East church ruins at st dunstan's hill create a secret garden sanctuary between tower hill and monument stations. Bombed in WWII, turned into public garden with climbing ivy. Incredibly peaceful and completely free.

Little Venice near warwick avenue tube has canal houseboats and willow trees that feel more amsterdam than london. Jason's canal boat trips start here at blomfield road. Much quieter than regent's park crowds.