For lovers of things that glitter and the applied arts, the Hermitage's Treasure Gallery should not be missed. Its two special collections, guarded behind vault doors, are open only by guided tour, for which you should either call ahead to reserve a place, or buy a ticket at the entrance.
The Golden Rooms collection focuses on a hoard of fabulous Scythian and Greek gold and silver from the Caucasus, Crimea and Ukraine, dating from the 7th to 2nd centuries BC; the Diamond Rooms section has fabulous jewellery from Western Europe, and pieces from as far apart as China, India and Iran.