Registered cover franked with 1957 'Galapagos Islands' DEFINITIVE issue set of six (SG 1/6) tied by undated SANTA CRUZ CORREOS ARCHIPELAGO COLON cancels in deep purple. Addressed to LIECHTENSTEIN but unclaimed on arrival with a variety of markings including large 'RETOUR' and small perforated 'Unbekannt Inconnu Sconosciuto' label tied by TRIESEN cds. Returned sender with GUAYAQUIL arrival cds on reverse.