Key Tower is a skyscraper on Public Square in downtown Cleveland, Ohio. Designed by architect César Pelli, it is the tallest building in the state of Ohio, the 39th-tallest in the United States, and the 165th-tallest in the world. The building reaches 57 stories or 947 feet to the top of its spire, and it is visible from up to 20 miles away. The tower contains about 1…Key Tower is a skyscraper on Public Square in downtown Cleveland, Ohio. Designed by architect César Pelli, it is the tallest building in the state of Ohio, the 39th-tallest in the United States, and the 165th-tallest in the world. The building reaches 57 stories or 947 feet to the top of its spire, and it is visible from up to 20 miles away. The tower contains about 1.5 million square feet of office space.