This month marks two years of engineering effort Cincinnati has spent to preserve one of our landmarks,   Cincinnati Union Terminal. The Terminal, built in 1933 in the   Art Deco  style, served as our railroad hub before becoming a museum devoted to both Natural History and the City of Cincinnati.  It is still the largest half domed structure in the Western Hemisphere.  During the process of restoration, the Union Terminal Crew has chronicled the progress via   monthly videos.