This month’s calendar features the granite marker noting the location of the original Chicago Pile-1 after it was disassembled and moved to the Argonne National Laboratory, Site A, in March 1943 and renamed Chicago Pile-2.

Now called the Red Gate Woods forest preserve, you’ll find an inscribed granite marker and an historical site marker. These mark the spot where Chicago Pile-2 was reassembled and built, along with other reactors. Chicago Pile-2 operated until 1954, at which time it was shut down and buried in Site A/Plot M Disposal Site. The gigantic hole dug was big enough for the 2-story high reactor, which was decontaminated and imploded for safety.

Other artifacts can be found in the area, including other concrete markers inscribed with historical information, the foundation of the labs, and more. The site can be found along the Pipeline Trail, which is poorly marked, but well worth the trek into history. Similarly, the trek from the main parking lot is as arduous.

Several markers near Site A/Plot M caution that radioactive material is buried in the area.

Be sure to download the November 2025 calendar featuring significant atomic events and atomic shots occuring during the month of November.