Yan Wo Tong is a Chinese tea shop in the western part of Mong Kok, in a basement unit of Kai Yue Commercial Building on Argyle Street. It serves cold tea and turtle jelly, including Hachocho cold tea, Huomaren, and a turtle jelly with a milder herbal taste. It stays open until 2 a.m., so it can be visited late at night. Aside from the turtle jelly, the menu centers on Chinese herbal medicine items, so the range of choices is narrow.