Constructed by Sir John Morris to house the families of workers, it is one of the earliest examples of a tenement building.

The castle consisted of twenty-four family apartments and was built to house the workers at the Treboeth Level Colliery and the copper works at Landore.

In their 1814 survey of the economy of south Wales, Gwallter Mechain and Iolo Morganwg praised both the castle and John Morris himself as "the most extensive individual builder of comfortable habitations for the labouring class.

He first erected a kind of castellated lofty mansion, of a collegiate appearance, with an interior quadrangle, containing the dwellings for forty families, all colliers, excepting one tailor, and one shoemaker.

"[5] In 1976, the Castle remains were listed as a Scheduled Ancient Monument by Cadw as a building "of national importance" and one of the first structures erected for housing workers in flats.