This 1970 Caritas semi-postal from Luxembourg depicts the medieval Clervaux Castle, originally built in the 12th century, with two figures in period costume adding a historical flair. Designed by Foni Tissen and printed by Courvoisier S.A., the stamp carries a face value of 50 centimes plus a 10 centimes surtax to support charitable causes. The rich detail of the castle highlights its enduring role in Luxembourg’s cultural heritage. A fine example of Luxembourg’s tradition of combining philanthropy and philately, this issue appeals strongly to thematic collectors of castles, architecture, and Caritas series. A sought-after addition to any European collection.