When a sinkhole opened up beneath the car park of a Kent branch of Primark, few would have expected it to have revealed such wonders.
But an astonishing network of underground tunnels that could date back a century was discovered under the Broadstairs retail complex - and history experts believe they may have been used during both world wars.
The tunnels containing rusted metal barrels and basins were first found after a similar incident of subsidence in 2015 by the landowners Westwood Cross and have since been explored by local group Thanet Hidden History.
Experts believe the British Army used the tunnels - accessed by steps - for training exercises, but have argued whether they were created before the First World War or after in preparation for future conflicts.
According to KentLive, a Freedom of Information request was sent to the Ministry of Defence by the landowners Ravenside Investments two years to delve into the origin of the tunnels.
Ravenside Investments wrote: 'We have recently discovered tunnels underneath our property and have reason to believe these were created by the Army during the First World War as a training exercise.'
But the MoD replied that 'no information' was held in its records on the tunnels. Thanet Hidden History believes an air raid shelter hidden under the shopping centre was sealed in recent years to prevent further damage.
The Primark - which has been on site since 2011 - reopened last weekend after being closed since May since the subsidence,