The Old Quarter (Vietnamese: Phố cổ Hà Nội) is located in the center of Hanoi and nearby Hoan Kiem Lake, the name commonly given to the historical civic urban core of Hanoi, located outside the Imperial Citadel of Thăng Long. This quarter used to be the residential, manufacturing, and commercial center, where each street was specialized in one specific type of manufacturing or commerce.
Another common name referring to approximately the same area is the 36 streets (Vietnamese: Hà Nội 36 phố phường), after the 36 streets or guilds that used to make up the urban area of the city.
The most famous trait of the Old Quarter is its areas dedicated to one specific trade or guild. Craftsmen from villages around the city used to gather in one area of their guild to sell their wares to merchants. The crafts or guilds of each area gave the names to the streets of the quarter so that most streets acquired names starting with hàng (“wares"), such as Hàng Tre street (“bamboo wares street") and Hàng Đồng street (“copper wares street").
Several of the streets are still specialized in the trade that gave them their names. Others still specialize in one specific trade, but a different one from their traditional specialties — such as Hàng Buồm street (“sails street") which has become dominated by Vietnamese cakes and candy.
The Old Quarter has been shown by researchers using the quantitative social anthropology approach to have exhibited Hanoi’s cultural evolution during the first decades of the 20th century.