;)
We purchased the wooden puzzle that's pictured on the right. It's very complex, apparently one of the hardest to solve. The process of solving involves taking it apart and putting it back together again.
A translation of the festival website is here.
Arc de Triomphe | The Sunday Bird Market | Context Tour "The Belly of Paris" | The Eiffel Tower | Houseboats on the Seine | Jeux Mathematiques (Mathematical Puzzles) Fair | Luxembourg Gardens | Miscellaneous | Montparnasse Tower | Paris Velo Rent-a-bikes | Shops and Storefronts | Toyota Showroom on Champs-Elysées