It is located near to the village of City Dulas.

Traeth Dulas is an enclosed estuary with extensive saltmarsh and mud and sand flats at low tide. The area supports a wide range of seabirds, shorebirds, waders and wildfowl, including gulls, dunlin, turnstone, and wigeon. In the winter time, the estuary is dominated by gulls and waders. Curlew can be seen using the pastures adjacent to the site, and purple sandpipers and other small waders may be seen on the shore to the seaward side of the shingle spit.

Birds of prey including peregrine and merlin hunt across the estuary, whilst hen harriers and barn owls may be seen patrolling the edges of the reserve. In the summertime, the estuary supports a variety of breeding birds, many of which use the area for nesting, feeding and rearing their young. Examples include oystercatcher, shelduck, redshank, red-breasted merganser and ringed plover. Sandwich terns and locally breeding grey herons regularly visit the site, as do mallard and lapwing.

The mudflats and inter-tidal zones will support a great variety of marine invertebrates, which are a source of food for the many waders and wildfowl. It is possible to park at the western end of the estuary, but be aware, the whole area becomes inundated at high tide, so it is worth checking the local tide times before you visit to avoid getting cut off.