Traeth Dulas is the wide sand and mud estuary of the Afon Goch river, which has a beach of coarse sand at its seaward end. The beach is backed by low sandy banks covered in marram grass. The headland to the south is Craig y Sais, and at low tide it is possible to walk around to Traeth yr Ora. The beach looks out towards the island of Ynys Dulas.
There are no car parks nearby, but the more westerly of the two car parks for Traeth Lligwy would be closest. From here, follow the lane back and take the coastal path for Traeth yr Ora, but instead of descending to the beach, continue along the path to an Open Access area. On reaching this, bear left towards the field boundary where you should see a stile. This leads to a short path down to the mudflats where you turn right, taking another path to the beach. Alternatively, there is space for roadside parking outside the Capel Elen Caravan Park, from where a public footpath leads over the hill towards the coastal path.
Portobello is a small sandy beach on the opposite side of the river, the seclusion of which is rather spoiled by the large house of the same name at the back of the beach. Parking space can be found at the end of the lane from Llaneuddog, at Grid Ref: SH477880. From here walk along the north side of Traeth Dulas to the beach. Note that this may require a little wading on a high tide.
At low tide it's usually possible to cross the river between the two beaches.