First Aluminum Observatory Dome. On the hill just west of here, the first known astronomical observatory with an aluminum dome was erected in 1930. Designed & built by Pittsburgh amateur astronomers led by Leo J. Scanlon, the Valley View Observatory stood beside his Van Buren St. home. In the ensuing years, many of the world's observatories were built with such domes. Scanlon's shiny metal dome became a model for the popular image of a modern observatory.