This 35 centavos airmail stamp from Costa Rica was issued in 1970 to commemorate Expo ’70, the World Exposition held in Osaka, Japan. The design features the “Torre del Sol” (Tower of the Sun), a central symbol of the exposition created by artist Tarō Okamoto. With the theme “Progress and Harmony for Mankind”, Expo ’70 showcased futuristic architecture, technological innovation, and international cooperation. The vibrant imagery and bilingual inscriptions (Spanish and Japanese) highlight Costa Rica’s participation in this landmark world event, making it a prized thematic issue for collectors of world fairs, architecture, and airmail stamps.