Caernarfon Castle Gatehouse

Accessing the history of this iconic site in north Wales.

Completed 2023
Heritage Consultancy

Areas of Caernarfon Castle that have not been accessed for centuries are now available for all to enjoy.

caernarfon castle

Recognised around the world as one of the greatest buildings of the Middle Ages, Caernarfon Castle is Grade I listed and a Scheduled Monument. It became Wales’s first World Heritage Site in 1986, along with those at Harlech, Beaumaris, and Conwy.

Project aspiration

The King's Gate, the monumental gatehouse and point of entry to the castle, forms part of the popular upper-level wall walk but is not accessible to all and falls short of its potential to add to the visitor experience. This has been the primary driver for the project which is complex and challenging; just the way we like it.

a sculpture on the deck at Caernarfon Castle

The concept

We have worked closely with clients Cadw, and a wide range of stakeholders, including ICOMOS, to test our ideas and create new contemporary architecture that is infused with, and responds to, the significance of this amazing place.

Our designs add a lightweight, textural form that sits onto and into the twin towers forming a sheltered platform on the upper level, a place to sit and reflect that is accessible to all.

an organic wooden bench at Caernarfon Castle

‘The hands that built the castle’

Interpretation is integral to the architectural approach and a series of experiences are created across the scheme that showcase stories alongside the new places revealed to visitors in the King's Gate. 

Internally, three new floors of accommodation have been created, housing accessible toilets with changing places, a café, a gift shop, a reception area, staff facilities, storage, and new and immersive interpretation areas that show how the spaces within the gatehouse were originally used.

This modern approach to interpretation aims to present the story of the castle from a different perspective and encourages visitors to form their own opinions on how they perceive the site’s history.

Insertions that touch the castle lightly

The new accommodation has been designed to form the negative of the King's Gate, with vertical access a key driver for spatial planning. On the upper level, the architectural forms emerge from the towers below to create a viewing deck with seating areas, allowing visitors to take in views across the castle complex and beyond. Access to the deck is provided via a glazed lift, which enables visitors of all abilities to access this part of the castle for the first time in its history. It is also believed that this is the first-time that access has been provided in any similar UK World Heritage Site.


This has involved the introduction of a new layer of architecture to the medieval building in the form of bespoke pieces of ‘furniture’ that sit on top of and within the triple-towered gatehouse. Designed to form the negative of the building the structure and architectural features have been created to be physically separate from the castle walls, only touching the building lightly at access points to minimise the impact on the significant historic site.


All new interventions consist of prefabricated units and hand-crafted, bespoke carpentry that can be inserted into and removed from the building with minimal impact on the existing structure. The detail and quality of the materials have been used to celebrate it as the grand gatehouse and high-status entrance to the castle, whilst reflecting the unfinished nature of the site through clearly contemporary additions

“Making our historic sites more accessible is a fantastic — and necessary — way of caring for Wales’ historical monuments for the benefit of present and future generations."
Dawn Bowden MS, Deputy Minister for Arts and Sport.

The result is a bold and innovative approach; challenging convention whilst revealing and enhancing the outstanding universal value of this remarkable place.

interpretation of the stonemasons input in front the caste walls
the illustrated ceiling
the gatehouse at Caernarfon Castle
the stonemasons sculpture at Caernarfon Caastle
detail of the spiral staircase at Caernarfon Castle

Conservation of the fabric

Conservation works to the King's Gate are being undertaken as part of the project. A very light touch approach is being taken to stone repairs, repointing, and cleaning.  Painstaking attention to detail underpins the conservation works and is evident in the repointing of the inner and outer elevations of the King's Gate and Battlements, where 13 sample boards have been made up to match the mortar to the walls which have seen phases of repair over time. 

Heritage Consultancy

Buttress' Heritage Consultants worked closely with the architectural team, client, and stakeholders to provide a sound understanding of the impacts of the design proposals on the significance of the World Heritage Site. A detailed Heritage Impact Assessment was undertaken following ICOMOS Guidance and was adopted by the team to help inform the design process and manage the consents process for the scheme. The bespoke document is being adopted as best practice by Cadw for future schemes that require this thorough understanding.

Talk to the team

Image credits 

Buttress: Sebastian Chambers, Stephen Anderson, Jenna Johnston, Lucy Ashcroft.