Llandudno Junction , once known as Tremarl, is a small town in the county borough of Conwy, Wales. It is part of the ancient parish of Llangystennin, and it is located south of Llandudno. It adjoins Deganwy and is to the east of the walled town of Conwy, which is on the opposite side of the River Conwy. The population is 6,722 (2011) and is part of the community of Conwy, and comprises the wards of Marl and Pensarn (Llandudno Junction).