Castleton Jail

In the early 19th century, Vermonters discovered beds of slate that stretched from the state's western edge to New York's eastern borders.

These massive deposits gave birth to a healthy mining industry that still extracts the grey, sea green, and red material.

The dark interior consists of two cells and a jailor's compartment with only a single window to admit light and air.

Special dollies with 24 rubber-tired wheels were built to carry the basic structure and demanded additional steering apparatuses and four sets of brakes to maintain control on steep hills.

The move, aided by the Vermont State Police, required three days at speeds up to 7 miles per hour (11 km/h).