This third issue of the definitive series of the early 1970s shows four of Portugal’s national monuments.
The 58km long Aqueduto das Águas Livres (Free Water Aqueduct) in Lisbon, built to bring fresh water into the capital, is an engineering masterpiece of the 18th century.
The Castle of Santa Maria da Feira in the Aveiro district, a major exemplar of medieval military architecture, played a fundamental role in the birth of Portugal and in the reconquest battles against the Moors.
The 16th century chapterhouse window of the Convent of Christ, a UNESCO World Heritage site in Tomar, is a masterpiece of the Manueline style.
The 15th century Palace of the Dukes of Braganza in Guimarães became a ruin in the 19th century after its stones were used for local buildings. The current palace, being the result of a controversial restoration from the mid 1930s to the end of the 1950s, is probably quite different from the original.
The set was designed by the Post Office Art Department, lithographed by the Mint on glazed paper sheets of 10×10 stamps with perforation 12½, and circulated from 5 September 1973 to 31 December 1983.
Most stamps were later re-printed, sometimes with a phosphor band (P in the table below). Stamps printed before 1978 have a continuous small grey security inscription (“CTT” followed by the year) printed on the back, over the gum. The Stanley Gibbons catalogue lists stamp 1451p as issued in 1979, and 1457p in 1976. The print run numbers are an attempt to reconcile the various numbers given in Kullberg’s album and the 1990 Eládio de Santos catalogue. In case of strong contradiction, the catalogue numbers were adopted as they seemed more realistic.
- Carlos Maia, Landscape and Monuments, A Filatelia Portuguesa (online edition), no. 102, January 2002. Accessed 22 November 2011.