Cathedral arch keystone. Artwork of the keystone for an arch in a medieval cathedral being lowered into place. The keystone completes the arch, allowing it to bear weight and the supporting scaffolding to be removed. These arches are part of Salisbury Cathedral, built between 1220 and 1258 in Salisbury, England. The architectural style is Early English Gothic (Lancet Gothic), which has as one of its defining elements the pointed arches shown here, sometimes called ogive arches or lancet arches. The construction material used for Salisbury Cathedral was Chilmark Stone and Purbeck Stone, both types of limestone.