The America Pavilion for the 1967 Expo in Montreal was as high as a 20-storey building, and soon became the focal point on the Île Sainte-Hélène site. In the space of six months it was visited by 5.3 million people, making it the busiest pavilion at Expo '67. It measures 76 metres in diameter, and 62 metres in height. During the Exposition, it contained 6 inner floors housing American artefacts. The structure was covered by a transparent outer shell composed of tinted acrylic panels, which later burned in a 1976 fire, shutting down the building for fourteen years. In 1990, Environment Canada purchased the site to turn it into an interactive museum, showcasing and exploring the water ecosystems of the Great Lakes-Saint Lawrence River regions. The new museum was completed in 1995 and is currently in operation.