Expo 67 was open from April to October, 1967 in Montreal, Canada. The site consisted of two islands and a peninsula in the middle of the St. Lawrence River. The admission ticket was referred to as a passport and entitled the holders to free entry to all pavilions as well as unlimited use of the mass transit system - Expo-Express. The passport could be filled with "visa stamps" at the National Pavilions. Via: http://www.alamedainfo.com/Expo_67_Montreal.htm
Mexico Pavilion, Expo ‘67, Montreal, 1967. Defined by a ‘fan’ of hyperbolic paraboloids, the ‘half’ of Mexico’s pavilion for this fair, seen here (the other ‘half’ of the pavilion featured a replica of an ancient Maya structure).