Open House Festival — Volunteer Stewarding

The 35th edition of Open House opens extraordinary buildings across London — private homes, offices, landmarks normally closed to the public — free for anyone to wander round. Volunteering to steward one for a shift gets you talking to a steady stream of curious strangers, plus priority entry to the rest of the programme.

A genuinely easy way in if you're going alone: you turn up with a job to do, so there's none of the awkwardness of a normal social event, and everyone you meet is there because they love the same weird old buildings you do.