Mangroves is located inland about 5-10 minutes walk from Railay West Beach. It serves excellent local Thai dishes at very good prices, much cheaper and more tasty than the places on the beach. You will definitely get great bang for your bhat at Mangroves!
The one thing that Mangroves is lacking is a grill for fresh seafood. But don't be alarmed, you can go next door to the Local Thai Food Restaurant (Organic Food) which allows you to pick out your fish or squid and watch it be cooked on the grill. Local Thai Food Restaurant does not seem to have a place for reviews on TA, but you can't miss it if you go to Mangroves.
I would recommend checking out both of these restaurants as they are both tasty and good value. However, be prepared for slower service. They were both quite busy on each visit (we went 3 times) and it took awhile to get our food. However, we found that many restaurants in Thailand were a bit slow on service, and at these two places, the food is definitely worth the wait! Just relax on some cold beers while waiting for the feast to begin!
This review is the subjective opinion of a TripAdvisor member and not of TripAdvisor LLC.