The Brunson Company is a precision tool company based in Kansas City that is a worldwide leader in the field of measuring technology known as metrology, used in a wide variety of industries from surveying to aerospace. In 1955, Mr. Brunson was seeking a stable location to build and calibrate specialized equipment, and decided to mimic the process used by local limestone miners to create an underground space for the company. Over a few years a bluff east of Kansas City was excavated, across from an existing mine, and a 140,000 square foot laboratory and factory opened in 1960. This was the first major commercially developed underground space in the region, and possibly the only intentionally created underground space, as opposed to the others, which were created as an unintentional byproduct of the mining process. The Brunson project, now expanded to 225,000 square feet, helped city planners and building safety officials see the possibilities, and the value, of the existing limestone mining caverns that ringed the city.