To enable each canton of Switzerland to be represented with at least one building of artistic or historical merit, new definitive stamps were issued on 12th September 1968, closing the 1960 series: Planta House (design). ("Helvetia Philatelic Society News Letter", Edythe Rawnsley, Ilford [London], 1968: 47)
country: Helvetia
year: 1968
Yvert: 818
![To enable each canton of Switzerland to be represented with at least one building of artistic or historical merit, new definitive stamps were issued on 12th September 1968, closing the 1960 series: Planta House (design). ("Helvetia Philatelic Society News Letter", Edythe Rawnsley, Ilford [London], 1968: 47)](https://encyclopaediaphilatelica.net/storage/uploads/62b9a25367152-php2cfqh8.jpeg)