The National Trust for Historic Preservation has released a list of the 11 most endangered culturally significant historic sites across America, helping to raise awareness and reduce the risk of these sites being lost forever.

Despite being threatened by neglect, development, climate change or lack of resources, these places tell unique stories about the country's architectural and cultural history.

Discover which important historic sites in the US we're in danger of losing...

While her name may not be as historically well-preserved, May Hicks Curtis is considered to be the ‘Betsy Ross of Arizona’ having sewn the first Arizona state flag back in 1911. Among other things, she was a college graduate, assistant postmaster, and photographer: she helped create the largest collection of early photographs of Flagstaff with her first husband Frank Curtis.

However, May’s home, much like her name, is in danger of being lost to history. 

May Hicks Curtis built the simple, single-story home, which dates back to 1913 and lived here for decades. It features a steeply pitched roofline, two central chimneys, and a stucco façade and sits adjacent to two boarding houses that May and her mother operated in the early 20th century, catering for travelers on the iconic Route 66.

In recognition of its historical significance, the City of Flagstaff took ownership of the property and is currently seeking to relocate it ahead of new development near the current site. As yet, however, the future of the May Hicks Curtis House hangs in the balance.

Situated in the Big Bend region of Florida’s Gulf Coast, Cedar Key is an archipelago of small islands with a population of roughly 700 people who have made these wetlands and woodlands home.

Small but significant, the area represents an increasingly rare example of what is culturally considered “Old Florida,” a concept associated with pastel-colored, wood-frame houses, and small coastal communities that survive on industries such as fishing, small-scale tourist attractions, and local businesses.

Like much of Florida’s Gulf Coast, Cedar Key’s waterfront region was decimated by a record-breaking storm surge brought on by Hurricane Helene in 2024. Many of the area’s historic homes were washed away, and the old city hall and post office were damaged.

But the small community is facing a much larger fight for survival. Data projections show that Cedar Key is at risk of significantly increased flooding risks in the coming decades. Plans to protect the area include raising and waterproofing vulnerable buildings, improving drainage around the historic cemetery and creating a more robust “living shoreline.”

This crumbling wood-frame resort represents a relic of a bygone era, when the Catskills became a popular vacation spot for New York City natives in the late 19th and early 20th centuries.

One of the few remaining examples of the early Catskills summer resorts, the Wellington Hotel, originally known as the Ulster House Hotel, has fallen into significant disrepair since its initial construction in 1882. 

While the resort’s location in Pine Hill, New York remains a popular tourist destination, the Wellington Hotel has long since ceased to serve the visiting community, with its crumbling foundations and structural instability.

A community initiative bought the building in 2022 and has shared plans to add a grocery store and café, plus some work/live apartments. Any attempt to shore up the building would require foundation replacement, flood mitigation measures, a fire suppression system, not to mention major renovations for the interior and exterior, with costs estimated at around $7 million. 

Across the mountainous regions of western North Carolina flow the French Broad and Swannanoa Rivers, each of which plays an integral part in the region’s vibrant arts scene and cultural identity. 

Along the banks of both rivers are dotted a collection of small, historic towns, including Marshall, Swannanoa, and Chimney Rock. They suffered severe flood damage in September of 2024, when Tropical Storm Helene made landfall along the Florida Gulf Coast.

Helene caused both rivers to swell to unprecedented flood levels, breaking a 100-year record for the area, and causing significant damage to historic structures in the surrounding region.

As many of the communities affected were not previously considered vulnerable to natural disasters, they were not located in ‘flood zones’ and lacked adequate insurance, significantly complicating restoration efforts. While local organizations are currently working on both recovery and conservation, significant funding is still required for both.

Situated in Idlewild, Michigan, Hotel Casa Blanca was once the premier resort destination for Black travelers and played host to some of the greatest entertainers of the day, including Louis Armstrong, Count Basie and Aretha Franklin.

Featured in the famous segregation-era travel guide for African Americans known as The Negro Motorist Green Book, the hotel came to be known as ‘Black Eden,’ drawing thousands of annual visitors by the 1950s.

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With the end of segregation, Idlewild, like many Black resorts, saw a significant drop in visitors and substantial economic disinvestment. Today, Hotel Casa Blanca has sat abandoned and deteriorating for 30 years, while its surrounding resort community has dwindled to just 700 residents.

However, hope glimmers for the historic property, as its former owner has sold it to a Black woman-led non-profit, which plans to restore the hotel into a bed and breakfast.

This unusual ‘castle’ in Phoenix, Arizona was hand-built between 1934 and 1945 by Boyce Luther Gulley for his daughter, Mary Lou, and combines organic architecture with folk art.

Although he lacked official plans, permits and formal architectural training, Gulley spent 11 years constructing an 18-room, multi-story structure from recycled and discarded objects. He was inspired by local materials in the Sonoran Desert and Indigenous cultures of the American Southwest and Mexico, bringing elements of stone building, carpentry and mosaic into the house and grounds.

After Gulley’s death in 1945, Mary Lou and her mother worked hard to maintain and promote the Mystery Castle, which had become a well-known tourist attraction and had even featured in LIFE magazine.

Though Mary Lou set up a small local foundation to look after the castle before she died in 2010, a series of break-ins and vandalism over the years have caused extensive damage, which the foundation lacks sufficient funds to repair. The house has been granted a one-year demolition stay to allow Facebook and preservation groups to coordinate their efforts and raise enough money to save this extraordinary labor of love.

The only lodging of its kind, the Oregon Caves Chateau was originally constructed in 1934 within the Oregon Caves National Monument and Preserve. The chateau provided tourist lodgings and was designed to incorporate elements of the surrounding landscape, including local wood, stone and even a nearby stream running through the dining room.

Consequently considered a peak example of 'Parkitecture,' the building has been designated a National Historic Landmark, and boasts the most extensive public collection of historic Monterey furniture in the US.

In 2018, the National Park Service closed the chateau to undertake extensive restorations to address structural deterioration and attempt to bring the building in line with current safety and accessibility standards.

However, once the construction began, it became apparent that the work needed far exceeded expectations… and their budget. The restorations are ongoing, but the timeline for completion is unclear, and the longer it remains unrenovated, the more vulnerable it becomes to damage from the elements.

Tsennacommacah in King William, Virginia has been inhabited by the Pamunkey people for at least 15,000 years. Today, the area has been designated as the Pamunkey Indian Reservation, a federally recognized sovereign Tribal nation and the oldest extant Reservation in the country.

Historically, they were some of the first tribes to encounter European settlers in the 16th and 17th centuries, but they never ceded their 1,600-acre peninsula on the Pamunkey River.

However, surrounded as they are by the Pamunkey River and marshlands on three sides and a sinking railroad embankment on the fourth, Pamunkey tribal lands are highly vulnerable to the impacts of sea level rise, increasing storm frequency and severity and land subsidence.

Sea level rise in particular is threatening everything from archaeological sites and historic buildings and homes, to the traditional food and medicine plants and clay deposits for pottery, which the Pamunkey people have relied on for centuries.

Originally built in 1920 to serve Anglo businessmen and political figures moving into the largely Mexican American area, the San Juan Hotel in the Rio Grande Valley of Texas has become one of the area’s most recognizable landmarks.

The hotel was built during a dark period of Texas history, which historians refer to as “La Matanza” or “The Slaughter,” a time of anti-Mexican violence often perpetrated by law enforcement, which included the extremes of massacres and lynchings.

The San Juan hotel is situated along the main road dividing an Anglo neighborhood from a Mexican American area, and was reportedly the location of several of these horrific crimes.

Although it is a state-registered landmark and one of the few remaining historic structures in the community, the hotel is now under threat of demolition to make way for new urban construction. A local advocacy group has assembled to save the building, which they hope will become a site for "truth-telling and reconciliation, and to foster a sense of community pride and identity."

While the Japanese American fishing village on Terminal Island in Los Angeles was once a bustling community of more than 3,000 residents, today, only two structures remain to commemorate its existence.

After Pearl Harbor in 1941, the Japanese American inhabitants of Terminal Island were forcibly removed – many to be incarcerated at the Manzanar War Relocation Site – and the government razed most of the residential and commercial buildings to prevent their return after the end of the Second World War.

Today, the only remaining buildings are the Nanka Shoten building, erected in 1918, and the A. Nakamura Co. building, erected in 1923. They were once a dry goods store and a grocery store, but they have stood vacant and boarded up for years and are rapidly deteriorating.

While an action is pending to get both sites designated as Los Angeles Historic-Cultural Monuments, the Port is still considering demolition of the buildings to make space for the busy container shipping that operates there. Here's hoping a spot on America's Most Endangered list will improve their chance of survival.

With its distinctive shape, the Turtle, also known as the Native American Center for the Living Arts, was built in 1981 by Arapaho architect Dennis Sun Rhodes. The building’s design was inspired by the Haudenosaunee creation story of Sky Woman landing on the back of a turtle, also known as Turtle Island.

The building is therefore regarded as a powerful symbol of Indigenous heritage, and is meant to symbolize the cultural reclamation and celebration of Native American languages, identity, and arts.

The Turtle was completed 15 years after the closure of the last federally funded Indian Boarding School – institutions which took Native American children away from their parents and communities and educated them in European cultural traditions – and was intended to serve as a hub for cultural education and preservation.

Once the largest center for Indigenous arts in the Eastern United States, the Turtle closed in 1996, and is now in danger of demolition as it's not a protected local landmark. This picture shows the turtle's head, which was once painted in black and white stripes to bring the animal to life.

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