The Sovereign and his son visited the exhibition yesterday, which runs until April 26, commemorating the passion of Prince Rainier III, who founded the museum in 1996.

With a deliberate stamp to cancel the first-day cover, Prince Albert II and his son, Hereditary Prince Jacques, officially opened the exhibition this Tuesday afternoon, celebrating the 30th anniversary of the Stamp and Coin Museum.

This anniversary was marked by the issuance of a stamp commemorating the museum's creation, which the princes canceled in remembrance.