I just discovered there's an ad hoc outdoor Cambodian market every Sunday in FDR Park in South Philly. It's on the side of the curving road that goes through the park, past the golf club entrance, just before the I-95 overpass.
There are about a dozen vendors: women sitting on low stools or on cloth sheets cutting up and sorting fruits and vegetables, people selling clothing and videos, others grilling beef skewers and marinated duck heads(!), $1 each. Others selling noodle dishes and other ready-to-eat food. Lots of Asian vegetables I don't know the names of, also squash vines and flowers, which are so hard to find in Philly.
Many of the customers are families having picnics in the park. Quite a scene!