Upton Castle is believed to have been built in the 13th century and stands close to a creek of the River Cleddau on land held by the Earls of Pembroke.

[3][4] Management of the gardens, which had been substantially improved in the early 20th century, was taken over by the Pembrokeshire Coast National Park and opened to the public in 1976.

[1] However, the park authority later withdrew their funding and since the property changed hands in 2007, the new owners and a team of volunteers have restored and reopened the gardens.

[6][7] Too small to be described as castle in the strict sense of the word, most sources refer to it as a "fortified mansion" although its towers are unusually strong in comparison with other examples.

[8] The medieval portion of the exterior stands to the north east of the range, which is dominated by three early towers, separated by short sections of curtain wall and surmounted by a plain parapet on corbels.