DuSable Park, sometimes referred to as Mount Thorium, the 3 acre patch of land between the Ogden Slip and the main branch of the Chicago River, was found in 2002 to have high levels of thorium. Decades ago, the Lindsay Light Company operated on that site and dumped contaminated material.
Amazingly, the waste has a radioactive half life of 14 billion years.
Ultimately, the Spire was not built due to severe financial shortcomings and not paying rent on time. Many of us, however, still hope that someone pulls through to continue the project.