The main building of the hotel and the cottages "White Horses", "Mermaid", and "The Salutation" had been a private estate called "Aber Iâ" (), developed in the 1850s on the site of a late 18th-century foundry and boatyard. Williams-Ellis changed the name (which he had interpreted as "frozen mouth") to "Portmeirion": "Port-" from its place on the coast; "-meirion" from the county of Merioneth (Meirionydd) in which it was sited. The very minor remains of a mediaeval castle (known variously as Castell Deudraeth, Castell Gwain Goch and Castell Aber Iâ) are in the woods just outside the village, recorded by Gerald of Wales in 1188.