. Plans were drawn up in 1967 by the New Orleans modernist architectural firm of Curtis and Davis and the building opened as the Louisiana Superdome in 1975. Its steel frame covers a 13 acre expanse and the 273 ft dome is made of a lamellar multi-ringed frame and has a diameter of 680 ft , making it the largest fixed domed structure in the world. It is adjacent to the Smoothie King Center.