Tunnels, car parks, scout huts and caravans... theatre is turning up in some unusual places.
Last month, Beth Steel's Ditch became the first straight play to be staged in a labyrinth of disused tunnels under London's Waterloo Station.
Her dystopian debut is set in Britain in the near future when civilisation has collapsed and men are sent to fight on a distant battlefront.
Although not specifically written for a subterranean stage, the drama is a perfect match for the dimly-lit, dank location.
The play itself unfolds on a pit of earth, surrounded by a moat of water. As you might expect, audiences are advised not to wear their best shoes.
"What the tunnels have is a sense of menace and a sense of scale that helps the drama," says Sam Hodges, artistic director of HighTide, who co-produced the play with The Old Vic.
The Old Vic acquired the tunnels in February 2010 to create a new arts venue. The theatre's 160 seats were donated by artist Banksy, who has already used the space as a cinema.
The unique location under a railway station does bring with it a certain... rumbling noise from the tracks.
The low growl of locomotives bound for Surbiton and Southampton punctuates the action of the play every three minutes or so.
Hodges says it isn't a problem.
"We soon discovered that the regular rumble enhances the play in many ways. And our sound designers work to incorporate it into the overall soundtrack.
"The play has an encroaching sense of doom, so this rumble throughout is almost a kind of metaphor for that."
How have the actors found it?
"They've really embraced it all - it's a huge credit to them. There's a dank smell, it gets into your skin - and they've had to do without the traditional showers and, indeed, toilets."
HighTide's 2009 show Stovepipe was staged in a shopping centre and underground car park in Shepherd's Bush.
"We needed a big space through which you could transport 100 people at a time," recalls Hodges.
Another play involved converting a scout hut into a Guantanamo barracks.
"Outside was a big American flag and barbed wire - it was quite an alarming sight in this sleepy town in Suffolk."
But he sounds a note of caution: "I think there is a fad for site-specific work and it's important that one doesn't just find a non-theatre space just for the sake of it."
Another theatre company which works in unusual spaces is Slung Low in Leeds.
The company has just moved into a new home within five railway arches in the south of the city known as the Holbeck Underground Ballroom.
Slung Low's artistic director Alan Lane is preparing for an outdoor project next month with Notting Hill's Gate Theatre called The Knowledge Emporium.
"It's a caravan that has been turned into a magical sweetshop," says Lane.
The idea is that people trade their stories and memories for sweets. It is all written down and then turned into a performance at a later date.
"We do quite bombastic shows usually. It's quite a new way of working for us," Lane admits.
"When you are performing in places that aren't theatres, you have to be a bit more open with the rules or else people think you're being a bit smug."
He points out that taking plays out onto the streets is deep-rooted in historical drama through things like Mystery plays.
"They took place in wagons and in squares, so this current trend for finding spaces to put theatre might actually be a turning back to the oldest roots we have.
"We're branded as theatre innovators but we're standing on the shoulders of quite a few giants to get here."
Slung Low's past projects include a show at London's Barbican - "The audience got kidnapped in a 4x4 and and taken to a car park where there were vampires running around".
A plaza outside The Lowry in Salford was turned into a military zone for Beyond the Front Line - complete with explosions.
Lane recalls that an audience leaving a nearby comedy show wandered into the middle of the action.
"They came out and there was an almighty bang and 2,000 people hit the deck."
Or it can something as simple as a golden phone box placed between two red phone boxes on a street in Islington.
"The amount of attention that got," says Lane. "It was just a tiny bit of magic."
Ditch is on at the Old Vic Tunnels until 26 June. The Knowledge Emporium will appear in Notting Hill from 19 July to 1 August.