Mystery Castle in Phoenix Named One of America’s 11 Most Endangered Historic Places

Phoenix, AZ (May 7, 2025) — The National Trust for Historic Preservation has named Phoenix’s Mystery Castle to its 2025 list of America’s 11 Most Endangered Historic Places, a designation that brings national attention to a singular local landmark facing a very uncertain future. Preserve Phoenix, the citywide nonprofit dedicated to advocating for the preservation of historic places, recognizes the listing as both an honor and a serious call to action.

“Being included on this list affirms the cultural and architectural significance of Mystery Castle – not just to Phoenix, but to the country,” said Erin Lindsey, President of Preserve Phoenix. “But it also underscores the urgent challenges we face to stabilize, protect, and ultimately reopen this site for public benefit. There is still a great deal of work ahead.”

A Landmark with a Fragile Legacy

Built by Boyce Luther Gulley between 1934 and 1945 as a gift for his daughter Mary Lou, Mystery Castle is an 18-room handmade structure that combines elements of folk art and organic architecture. Its construction from recycled and salvaged materials, and its prominent location near South Mountain, made it a fixture of local lore and a popular destination for decades.

For many years, Mary Lou and her mother, Frances, lived in the home and welcomed visitors. But since Mary Lou’s passing in 2010, the property has fallen into disrepair, suffered multiple break-ins, and seen diminishing public visibility. In 2023, the private foundation entrusted with its care – lacking the resources to maintain or operate it – applied for a demolition permit. The City of Phoenix denied the permit, initiating a one-year stay to allow preservation alternatives to be pursued.

Toward a Viable Future

A conditions assessment commissioned by the Phoenix Historic Preservation Office in 2024 found that stabilizing the structure would require at least $1.3 million, with full restoration and public accessibility upgrades pushing the total closer to $3.3 million. In response, Preserve Phoenix is joining with the newly formed Friends of Mystery Castle Task Force to lead a grassroots preservation campaign. Community meetings, new partnerships, and a surge of public interest are driving the effort forward—but national recognition is vital to success.

“Preserving this remarkable landmark and reopening it to the public will ensure that Phoenix residents and tourists can once again appreciate this unique art environment and learn from its many stories,” said Carol Quillen, President & CEO of the National Trust for Historic Preservation.

“The 11 Most Endangered designation can serve as a catalyst,” Lindsey noted. “It opens the door to potential partners and funding sources that might not have been available otherwise. But our responsibility now is to translate this recognition into real, on-the-ground progress.”

Part of a Larger Arizona Story

Mystery Castle joins a growing list of significant Arizona places that have received national attention through the National Trust’s endangered sites program. Past listings have included the Mountain View Officers’ Club in Fort Huachuca, Camp Naco, Oak Flat, the Sunshine Mile in Tucson, and segments of Route 66. Local and statewide preservation organizations have actively led and continue to pursue advocacy efforts for each of these sites.

“These designations are never about nostalgia – they’re about what communities risk losing and what we can still save if we act together,” Lindsey said.

"Boyce Luther Gulley's Mystery Castle is a stunning art environment – an example of what one dedicated person can achieve with creativity, resourcefulness, and a vision. We are grateful to the National Trust for Historic Preservation for granting this critical recognition and heartened by Preserve Phoenix's efforts to ensure this vulnerable site remains a cultural and creative resource for the public foryears to come," says Annalise Flynn of SPACES (Saving and Preserving Arts and Cultural Environments).

Next Steps

Preserve Phoenix is committed to ensuring that Mystery Castle remains part of Phoenix’s story. With broad community support, thoughtful planning, and sustainable partnerships, there is still time to protect this remarkable place.

To learn more about the effort and how to get involved, visit preservephoenix.org or follow @PreservePhoenix on Facebook or @preserve_phoenix on Instagram.