Grimes Graves is the UK’s largest known Neolithic flint mine. Set in Norfolk’s Breckland Heath, it’s a rare site where visitors can descend into a 4,500-year-old mine. The new building over Pit 1 improves access, interpretation, and long-term preservation of this internationally significant site.

The structure had to meet strict constraints. The site is a Scheduled Ancient Monument and a Site of Special Scientific Interest (SSSI). The building could not touch the existing concrete slab or impact the protected landscape.

Our solution is a circular timber pavilion that ‘floats’ above the pit. A gently sloped ramp wraps around it, offering inclusive access and a sense of descent through time. Dates from the site’s history are inscribed on the structure, enhancing the interpretive experience. At its centre, a glazed oculus draws natural light into the pit below.

The interior offers interpretation, digital projections, and a place to prepare for the physical descent. For those unable to access the mine, a virtual tour provides a meaningful alternative.

The design uses natural, low-carbon materials including timber and zinc. The structure is demountable and designed for longevity. It requires no heating and minimal lighting. Bats still access the pit freely, while the building protects it from weather and erosion.

Community engagement shaped the project throughout. 23 organisations and community groups were involved through consultations, events, and volunteer programmes. The site now hosts storytelling clubs, learning activities, and inclusive visitor experiences.

Grimes Graves has become a cultural, social, and ecological asset. It welcomes more visitors, supports the local economy, and preserves one of Britain’s most remarkable prehistoric sites.

Link to Grimes Graves

Awards

Structural Timber Awards - Retail and Leisure Project of the Year
Civic Trust - Civic Trust Commendation
IStructE NW - Most Sustainable Project
Building Awards - Small Project of the Year Highly Commended