We'll miss it again this year, but sounds like great fun!
Come and hunt Paris treasures. The treasure hunt is free and open to all. You can enrol here or in front of the town hall of the 3rd, 6th, 9th, 11th, 12th, 13th, 18th, 19th and 20thdistricts and Saint ouen on July 3rd. The surreal adventure organized by Paris City Hall will be a unique way to discover the city, its secrets and its inhabitants.
[From Les Trésors de Paris 2010 - In search of the eternal roses - Rules of Paris treasure hunt]