Las Costas Nayaritas is unique. There is nothing like this restaurant in the city. It is an eatery focused almost purely on coastal Mexican seafood combinations. The closest to this theme was the old U.S.S. Vallarta, now long gone from Gwinnett Place Mall. There was a restaurant similar to this that I saw in Dallas, Big Shucks, but Big Shucks was largely oriented towards shrimp cocktails of various kinds, inexpensive beer, and futbol on large television screens.
I showed up at this restaurant a day before their Grand Opening, at a time when their lunch menu was also their dinner menu, and so the lunch I had may not be the lunch offering you get. What I saw were a lot of staple seafood varieties and not a lot of exotica. There were things on the menu like crab, clams, oysters, shrimp, and octopus. Fish included tilapia, salmon, and perhaps a flatfish or two. There aren’t many exotic or rare items.

Tortillas are large, crisp, corn based and a little granular on the tongue. The free tostada appetizer is better than anything I ever had at Lobster House.
The plates of food tend to be expensive, relative to prices you might see at a Red Lobster. But by way of compensation, the serving sizes are *enormous*. No other word for it, enormous. This is a place to feed a lot of people with a few plates of food.
What I ordered was the filete relleno, which Google tells me translates to ‘stuffed filet’. In fact this is a filet of tilapia over which a mixed bag of seafood and white cheese is poured. Again, the serving easily could have fed two and for the price, was actually a generous amount of food.
I spent a lot of time fishing the interesting bits out of the white cheese and trying them out. The dish was delicious. The octopus ran a little chewy but it was sliced so thin that wasn’t an issue. In the mix were things like fish, shrimp, octopus, crab meat, sauteed mushrooms, and various vegetables.
The sheer novelty of the restaurant has me contemplating it still. I think what would work best for most folks is to go in groups, buy one or two plates and share. I don’t think it has small amounts of food for small eaters. Serving size tends to be enough for two normal eaters (or one Chloe Morris).
Update 9/8/2013: as Emily of Spatial Drift points out, the style of this cuisine is Nayarit. A nice introduction to Nayarit cuisine online can be found here.
Las Costas Nayaritas
1555 Pleasant Hill Road
Duluth, GA 30096
(678) 635-6000