Scotia Investments who at this time owned Flamingo Park and various other attraction had a small seasonal dolphin pool sited at the castle which is located at St Asaph in North Wales for one summer in the early nineteen seventies. The castle is actually a folly and is currently a waiting restoration. Wikipedia Link
A Review of Dolphinaria states:
North Wales - near St Asaph. Owner: Scotia (Flamingo). Open: about 1970 for one or possibly two summers. Dolphins: from Flamingo. The free-standing, plastic lined, portable tank was said to leak, leaving the animals stranded. There were also said to be major filtration problems. Trainers: Mr B. Lyle and Ms D. Lyle.