The Clerkenwell Clown Caper is the latest in a series of more than 50 downloadable self-guided Treasure Trails based in and around the capital.

The plot involves circus entertainer and part-time PR exec Lottie Goodwill who has been found with her head buried in an enormous foam-topped pie in a Clerkenwell cafe. A clown was spotted running from the scene carrying a pair of over-sized shoes.

The Trail's theme was inspired by one of Clerkenwell's famous ex-residents, Joseph Grimaldi the 19th century clown, who lived in Exmouth Market for a decade and now has a blue plaque outside his former home.

Lasting around two hours, the aim of the Trail is to solve a set of fiendish clues incorporating plaques, signs, statues, monuments, images, engravings and other landmarks.

The Clerkenwell Clown Caper is the creation of Treasure Trails' Kathy Brown, who has written all of the London Trails including; 'The Missing Royal Wedding Ring Trail' in St James' Park, 'The Muswell Hill Menagerie Murder' and 'Lion Hunting in Stoke Newington'.

Designed to appeal to all ages from six to 106, the Trails cost £6.99 and are suitable for groups of up to five. They can be downloaded direct from the Treasure Trails website and printed immediately or sent in the post.

What: New Treasure Trail in Clerkenwell London

Why Try a Treasure Trail: A fantastic way for families and groups to explore towns, cities and villages across the UK with a self-guided themed walk.

Price: Treasure Trails cost £6.99 (plus P&P if required)

Website: www.treasuretrails.co.uk