Big splash: get bankside for Totally Thames, the best annual river festival anywhere (September 1 to 30)

Grateful dead: Nomad open-air cinema pops up among the graves at Brompton Cemetery (September 5-7)

Objection! Ian Hislop of Private Eye unsettles the British Museum (from September 6)

Art of thought: the Royal Academy hosts a Festival of Ideas for its 250th birthday - big names, big ideas (September 7 to 16)

Playtime: new Videogames: Design/Display/Disrupt show opens at the Victoria & Albert (from September 8)

The other royal family: Pearly Kings & Queens Harvest Festival at Guildhall Yard, City of London (September 16)

Nosey parkers: see inside normally-private buildings during Open House London (September 22 & 23)

Big draw: annual London Design Festival hits venues across the city (September 15 to 23)

Indie flicks: Raindance Festival showcases indie talent across West End cinemas (September 26 to October 7)

New moves: Dance Umbrella celebrates its 40th birthday with capital-wide dance events (September 26 to October 17)

Feast from the east: the Japan Matsuri brings food, fashion and culture to Trafalgar Square (September 30)