For 3 days, the bare bricked and musty tunnels under Waterloo station have been home to Slapdash – London’s first ever Improv festival. Improvisation, that is. Using nothing more than themselves, a guy on piano and a few shouted suggestions from the audience, a unique performance is simultaneously thought up and acted on the spot by a team of actors. Needless to say, what one sees is a one off occasion. Which means anything can go down. Be prepared to discard all previous preconceptions and experiences of the theatre.

Thursday 22nd July was MusicBox, The Maydays and The Scat Pack’s turn to dazzle the audience. As per our instructions, MusicBox would perform a musical entitled Robot, the Musical. Set in Ikea. One marveled at the crew’s ability to make up and sing songs about flat pack furniture that weren’t completely asinine, although they didn’t come without their own toe-curling moments.

Next up were the Maydays, from Brighton. Sketch show with one or two comic songs thrown in, this troupe improvised based on a short monologue delivered (incidentally by a member of MusicBox) after another audience-suggested word.

Their humour was dry, sick and slightly twisted: absolutely brilliant - a group one can easily envisage making it onto TV.

Following them was The Scat Pack. Their aim: to make a blockbuster movie. This one would be set in the catacombs of Paris. The protagonist: a man brought up by tunnel-dwelling pigs. His mission: to save the day from his evil, pig smuggling father. Nothing could have prepared the audience for what was to be such an abdominal-aching and side-splittingly funny piece that palpably buzzed with energy. The flow was tight, helped by the director who steered the sketch along and turned moments that could have failed miserably into something twice as funny.

The acts became better dressed and funnier as the evening progressed, with certain members standing out and performing consistently, but each and every actor gave it their all right the way through. The evening concluded with all three groups taking part in an Improv Jam. Which, although starting off punchy, quickly lost momentum…yet detracted nothing from what was a delightful evening.

Located in the Leake Street– the graffiti splattered alleyway home to many an urban music video – the tunnels offer an intriguing, slightly pungent, but very original venue for a night at the theatre. The air is dank, the ushers friendly and bar wonderful (serving drinks at very affordable prices, considering) which slightly makes up for the fact that the loos are of the portable variety.

The Old Vic Tunnels are an offshoot of the Old Vic theatre (were Kevin Spacey is artistic director) and have made a comeback this year after a successful season in 2009. The space offers “innovative and surprising” theatrical events, at affordable prices, aimed at attracting a younger, more Metropolitan audience.

Watch out for some of the pop-up events and film screenings as well as PLATFORM, the free production that concludes the season. The auditions on 7-8 August are open so if you fancy yourself a budding starlet, or simply want to do something impulsive, log on to