What is "rhos-on-sea"

Rhos-on-Sea , also known as Rhos or Llandrillo, is a seaside resort , community and electoral ward in Conwy County Borough, Wales. The population was 7,110 in 2001, increasing to 7,593 at the 2011 census. It is a mile to the northwest but effectively a suburb of Colwyn Bay, on the coast. It is named after the Welsh kingdom of Rhos established there in late Roman times as a sub-kingdom of Gwynedd, and later became a cantref (hundred).