The tallest building in Ohio is the Key Tower, which stands at 948 feet tall and was completed in 1991. At 410 feet high, the Wexner Medical Center's new patient tower ranks among the 10 tallest buildings in Columbus.Cleveland landmark Terminal Tower was supposed to be a modest train station in the heart of the city, but it turned into so much more. In this video we take a look at Cincinnati, OH, a city with a nice and skyline. Of these, City Hall is the largest and most impressive, and it was its nine-story clock tower that drew me here from a few blocks away in the first place. Key Tower in Cleveland is the tallest building in Ohio and a marvel of postmodern architecture. This list of seemingly random items represent landmarks in Ohio's race for the next biggest thing, and each has its own special story.