In the 18th century, the introduction of pumping to extract the brine from beneath Droitwich led to subsidence in some parts of the town.

Nowhere is this more evident than in the High Street, which sank in the middle, causing the buildings to lean into each other.

Hereford House, the light coloured building in this picture, has housed a butcher’s shop for decades but was once a pub called The Wagon & Horses.

Following subsidence its canny landlord changed the name to The Crooked House and traded on the building’s peculiar angles and sloping floors.

In one optical illusion, customers could place a ball on a table and watch open-mouthed as it appeared to roll up hill.