Almost every wall, ceiling, door handle and light fitting in Freemasons' Hall bears a symbol drawn from antiquity, the zodiac or the Old Testament.

"Most of it doesn't mean anything, it's just adornment. Of course, people are tempted to read odd things into every decoration," says Provincial Master Chris Connop. Lodges' checked carpets have, for instance, been wrongly linked to a similar design on police hats.

However, symbols taken from construction and stonemasonry are important to freemasons' ceremonies. Ashlars - rough rocks made smooth by a stonemason - are used to represent a member's progression through "the Craft".