Accoya at Caernarfon Castle, a UNESCO World Heritage Site

At Caernarfon Castle, on the banks of the river Seiont in north-west Wales, an observation terrace and seating areas in Accoya wood have been installed as part of a £5 million conservation and development project carried out with Cadw, the Welsh Government’s historic environment service. Inscribed as a UNESCO World Heritage Site in 1986 — the first in Wales — the castle is opening parts of its medieval keep for the first time in centuries, with a rooftop terrace, new floors in the towers and a lift to the ramparts. Buttress Architects specified Accoya for its tones close to the original masonry and its natural patina, its durability and its low maintenance. The interventions, physically separate from the walls, remain reversible and respect the minimal impact required on the historic structure.