Robert Ilg, a successful businessman, built a 22-acre park, Ilgair Park, during the 1920s with two large outdoor pools, which needed to be supplied by a large outdoor water tank. Ilg was concerned about preserving the natural beauty of the area and decided to build a replica of the Leaning Tower of Pisa to conceal the water tower.
The tower would be half the size of the original in Pisa: 94 feet tall, 28 feet in diameter, leaning 7.4 feet, and would be built with reinforced concrete. Construction began in 1931 and was completed in 1934.
In 1960, the descendants of Robert Ilg donated part of the park for the construction of the Leaning Tower YMCA. Arrangements were made to turn over the tower to the Niles YMCA with the condition that the YMCA would spend a minimum of $500 annually to upkeep the tower and surrounding area until the year 2059.
The tower soon showed signs of aging. Cracks in the concrete widened with every freeze-thaw cycle, and the $500 annual budget to upkeep the tower and grounds proved inadequate.
In 1991, the Village of Niles established a sister city pact with Pisa, Italy, and in 1995, after leasing the area and tower from the YMCA, the Village of Niles began a $1.2 million renovation project. Concrete was repaired, new lights were added to each of the eight floors, and a plaza was developed around the tower with four fountains, a 30-foot reflecting pool, a "telefono" booth, and landscaping. The Leaning Tower Plaza was formally dedicated June 26, 1997.
The Leaning Tower sits in Niles at 6300 W. Touhy Avenue.