Travis Kelce’s Secret Archive in a Cave 150 Feet Below Ground Includes 1 Surprising Item: ‘It’s a Big Deal’ (Exclusive) The Kansas City Chiefs tight end has a box of items preserved in SubTropolis, a 1,260-acre space created through the mining of limestone Original Source: https://people.com/travis-kelce-secret-archive-subtropolis-cave-150-feet-below-ground-exclusive-11796462