This striking Belgian semi-postal stamp features the historic Orval Abbey, highlighting medieval monastic architecture and architectural planning traditions. The design portrays monks studying architectural plans, symbolizing craftsmanship, spirituality, and reconstruction associated with the famous Trappist abbey. Issued as a charity (semi-postal) stamp with a 5F postal value plus 10F surtax, it supported social or cultural causes. The detailed engraving and architectural theme make it highly desirable among monastery, religion, and architecture topical collectors. A classic mid-20th-century Belgian cultural commemorative.