Located at 3 East Diamond Avenue, the Thomas Cannery operated from 1918 to 1962 and was the only food cannery in Montgomery County, as well a major employer in Gaithersburg. The cannery was damaged by a fire in 1962 and never resumed operation after that. The photo on the left was taken in 1986 and as you can see, an excellent job was done in preserving this structure, which now houses offices as well as a spa.