Heritage Arts Company are currently organising the second edition of VAULT festival, a six-week event programming all kinds of performance into the network of tunnels near Waterloo Station (formerly the Old Vic Tunnels, and before that a storage facility for British Rail).
The exact date is to be confirmed, but the festival will start in late January 2014. Four shows will be chosen to have a one-week run (in one of two small spaces - 90 seats and 50 seats), with the artist/company receiving 80% of the box office sales.
For more information on the venue and to apply see here. Deadline is 14 November 2013.