Musée Le Secq des Tournelles

Home to one of the world’s premier collections of wrought iron, this riveting (excuse the pun) museum is an astonishing sight, showcasing the extraordinary skills of pre-industrial iron- and locksmiths, in a magnificent setting across two floors within a desanctified 16th-century church.There's everything from elaborate penknives to candle snuffs, beds, fortified chests, candelabra, miniature pistols and intricate keys.