Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Peoria Mineral Springs is 14,500 year old natural spring in the city of Peoria, Illinois, United States. The site, also known as Spring Hill, is located on a hillside on the historic West Bluff. In 1843, a "cave-like barrel-vaulted brick reservoir" was constructed; the structure is concealed within the hillside and captures the flow of three separate springs. The brick reservoir was built for Peoria's first water company, prior to that the site was a Native American campground. Artifacts can still be found around the site. The site was added to the U.S. National Register of Historic Places on March 5, 1982.