Mather Tower is a Neo-Gothic, terra cotta-clad high-rise structure in Chicago, Illinois, United States. It is located at 75 East Wacker Drive in the downtown "loop" area, adjacent to the Chicago River.
The 521-foot-high building is sometimes called "The Inverted Spyglass" by Chicagoans due to its highly unusual design, an 18-story octagonal tower atop a more conventional 24-story rectangular "box." Briefly the tallest building in Chicago at the time of its completion in 1928, it remains the city's most slender high-rise structure at only 100 by 65 feet at its base. The interior space within the upper octagonal spire contains the least square footage per floor of any Chicago skyscraper.
Wikipedia https://en.wikipedia.org/wiki/Mather_Tower
Coordinates 41°53'15.415" N -87°37'31.517" E
