Overground Underground is a performance in which a cardboard Tube train, designed by William Alexander, will collect visitors and take them on an improbable route between Kensington (Olympia) and Holland Park, taking in sights such as the Napoleon Garden and the Orangery. It's safe to say you'll need your imagination working overtime for this one.
Overground Underground is part of Kensington and Chelsea's InTRANSIT festival. "Performances" are free, run from Wednesday 24 July - Saturday 27 July, from 10am-11.30pm and 12.30pm-2pm, with 4pm matinees on Wednesday and Friday. All weather permitting, of course.