Ruthin is the county town of Denbighshire in north Wales and an area in the southern part of the Vale of Clwyd. The older town, the castle and also St Peter's Square lie on a hillside, yet lots of newer components in the flood plain of the River Clwyd. This arised numerous times in the late 1990s-- flood-control works costing £ 3 million were completed in fall 2003. Ruthin is skirted by towns such as Pwllglas and also Rhewl. The name originates from the Welsh words rhudd (red) and also hubbub (ft), reflecting the colour of the sandstone bedrock, of which the castle was built in 1277-- 1284. The initial name was Castell Coch yng Ngwern-fôr (Red Castle in the Sea Swamps). The mill is nearby. Maen Huail is a registered ancient monument attributed to the sibling of Gildas as well as King Arthur, located outside Barclays Bank in St Peter's Square. The population at the 2001 Census was 5,218, of whom 47 per cent were male and also 53 percent woman. The average age of the population was 43.0 years and also the population is 98.2 percent "white". According to the 2011 census, 68 percent were born in Wales as well as 25 percent in England. Welsh speakers make up 42 per cent of the town's population.