Whenever I shopped at Costco in Concord, I wondered about the market at the corner of Monument and Detroit, which has a butcher paper sign covering the windows. Finally went in a couple of weeks ago, and found a nice variety of Asian, Latin and Indian vegetables, as well as fruit. They routinely carry baby yu cai (fresh and tender) and baby bokchoy, mexican and asian cilantro, 2 types of daikon, several types of fresh herbs, at least 4 types of hot chilis, and other vegs that weren't familiar to me. The prices are pretty reasonable. There were a number of Chinese and Indian moms shopping there. The ladies at the counter are Hispanic. There is also a seafood market in the back, with whole fish, crabs & lobster, but the prices weren't as good as at Ranch 99. There are also canned & packaged products, spices, rice, etc. and an aisle full of tortillas and breads. It is nice to have another produce market in this section of the East Bay. It's not very big, so you have to maneuver around carefully, but the 2 times I have gone, the produce has been of good quality.