The Greater Penobscot Building, commonly known as the Penobscot Building, is a skyscraper in downtown Detroit, Michigan, United States. Rising 566 feet (172.3 m), the 47-story Penobscot was the tallest building in Michigan from its completion in 1928 until the construction of the Renaissance Center's central tower in 1977. The tower has 2 basement floors, and 45 above-ground floors, for a total of 47. The building is located in the heart of the Detroit Financial District. The Penobscot is a hub for the city's wireless Internet zone and fiber-optic network.