The Triumphal Arch (1962-63, listed Grade II 1971) was built at the suggestion of Clough's daughter Susan and her husband Euan who pointed that a new way in was needed for delivery lorries that were unable to pass under the Gate House and Bridge House arches. Clough was not sure about a new roadway but when a Triumphal Arch was mentioned he immediately became interested. He soon produced a sketch (left) of a Rococo style gateway with rusticated arch beneath a high pediment inscribed by two massive scrolls. Note the change to a rounded top in the finished work. The statue in the arch is an early nineteenth-century wooden model for a series of lead Caryatids illustrated in Weaver's English Leadwork (London 1909) with the note: "On a balcony of a house in Park Lane are lead Caryatids, and very graceful they are with their windswept draperies. They were erected about eighty years ago, and their great weight nearly pulled down the whole balcony. " The Mermaid shields were cast in concrete (the plywood template designed by Clough can be seen in the Dome).
To the immediate left of the Triumphal Arch is a small piazza (1962-63, listed Grade II 1971) with five Classical caryatids (one by Jonah Jones) and a dolphin fountain. There is also a large Coade stone vase at the centre. From here paths radiate into the Gwyllt gardens. Close by is a Chinoiserie wrought iron ornament which fronts the main path into the Gwyllt.
Overlooking a pond on the back way in immediately behind the Triumphal Arch there is an ornate balustrade presented to Clough by the Dean and Chapter of Westminster Abbey in 1972. In the photograph, taken just after the balustrade was rebuilt, Clough stands alongside his masons (left to right) Trebor Owen, Jeff Muscroft, Twm Davies and Stan Thompson.
On the main path into the Gwyllt is the Playhouse (1962) where an Audio Visual presentation can be seen. Clough recorded his commentary for this in 1973. The original Audio Visual was arranged by Bruno de Hamel. It was revised in 1984 by John Morton. The Audio Visual plays on the hour and half hour throughout the day.