Zhenjiang's signature contribution to Chinese cuisine is its black vinegar — aged and fragrant, it transforms the dipping sauce for crab soup dumplings from a condiment into part of the dish. The local version of guotie (pot stickers) and soup dumplings is served throughout the city; the best places are the canteens near Xijindu and the old market streets. Zhenjiang pot-head meat (Zhenjiang Tangbao pork), braised and cooled until the collagen sets into a natural aspic, is the city's other notable speciality.