The Armory is the largest cobblestone building in the USA. It was originally meant to be made out of brick, but due to cost cuts it was built out of free and plentiful cobblestones. 3300 wagon loads were hauled from the nearby Clear Creek in 1913.
Atop Lookout Mountain is the Boettcher Mansion built in 1917. Constructed with local timber and stone, it's as perfect an example of the Arts & Crafts period as you can find.
The Mansion is furnished with a huge collection of original Stickley furniture, all in mint condition.