The estuary of the Krabi river is listed as Ramsar wetland number 1100 since July 5 2001. The protected area of 213 km² covers more than 100 km² of mangrove forests and 12 km² of up to 2 km wide tidal mudflats. The area is popular with birdwatchers coming to spot some of the most diverse and rare species in the world, the masked finfoot and the brown-winged kingfisher to name just a few.