I finally made it to the new Great Wall Supermarket on Gallows Road in Merrifield, about a quarter mile from Han ah Reum. They aren't yet completely up and running--according to big signs on the walls, they are planning to have sushi, a liquor department and prepared Chinese food, but these departments are not happening yet.
The store is brand new, and is quite a bit cleaner than the funky HAR, In general I would say that probably due to fewer customers and consequently less turnover, the produce wasn't quite as fresh-looking as HAR's--especially the greens. They had several unusual fruits I'd never seen for sale fresh before: mangosteen, rambutan, jujubee, and a couple I can't remember the names of that I'd never heard of before. There were at least a dozen different varieties of pears. I was looking for quinces, but they didn't have any. I did get some nice Muscat grapes and very inexpensive prune plums.
There were many different live and lively fish in their tanks--over at HAR, there were several dead Tilapia in the tank. At Great Wall, the clams are kept in water, and looked quite appetizing. They had a nice variety of fish filets and steaks, as well as whole fish-- though not the many different varieties that HAR has. They had lots of fresh, whole ducks in the meat case. Of course, the ducks with heads were labeled "ducks without heads" and the ducks without heads were labeled "with". The "packed on" date was October 30, (today is October 17), so no one with much of a command of English is keeping an eye on things. They had something I've never seen before: ground pork fat, sold like hamburger, by the pound. Presumably for making sausage. But I bought 2 1/2 pounds and rendered it in a baking pan in the oven, and made some lard, and ended up with a separate tub of crumbly cracklings.
The packaged and canned goods seem similar to HAR--but everything looks very fresh and new. Prices are similar. Lots of room in the parking lot.
