Courtesy of Jennifer Black/Usaj Realty
Denver architect William Lang designed the castle in 1889, per Realtor.com. Lang constructed the fortified castle with 22-inch thick lava stones.
The current owners of the house bought the castle for $1.58 million in 2019, listing agent Jennifer Black of Usaj Realty told Realtor.com. They bought it just before COVID-19 and spent the pandemic renovating the entire house, Black added.
The current listing price is a 122.2% increase from its 2019 sale price, according to Zillow.
When reached for comment, listing agent Black pointed Insider to the property listing for details.