Les Portes de Givre by Sabine Mirlesse was a series of seven frozen passages sculpted by Atlantic winds during the winter of 2022/23, an ephemeral Land Art installation inspired by the discovery of her grandfather's engineering research into frost behaviour at altitude in the 1930s, and a nod to the Gallo-Roman temple of Mercury, a pilgrimage site for centuries atop the Puy de Dôme volcano, uniquely positioned above the mists and clouds. Seven portals were installed following the Pleiades constellation, designed to encourage ice and frost formation through the site's microclimate, growing only to melt with spring's arrival; the project, Mirlesse's first public art installation, grew from her discovery, during lockdown, of a box of 1930s black-and-white photographic negatives documenting her grandfather's scientific research on frost's effects on aircraft wings for the air ministry, a wintry archive matching a volcanic terrain.