The site where George Washington was inaugurated as the United States' first president in 1789, is on a preservation group's list of 10 most endangered U.S. parks or monuments.
The original Federal Hall housed the first U.S. capitol. But that building was destroyed in 1812.
The structure, which stands in its place, was completed 30 years later. A statue of George Washington dominates the entrance. Inside, exhibitions explore the early years of the U.S. government, including the adoption of the Bill of Rights.
But structural damage is evident in the thick cracks crawling along the walls on every level.
The fractures have been visible for more than 70 years. Steve Laise of the National Parks Service, which cares for the monument, says that the cracks became noticeably thicker after the nearby World Trade Center collapsed. He worries that they could endanger the historic site.
"When the World Trade Towers collapsed, there was a seismic wave that went through the earth beneath us here," he said. "And we don't know exactly what happened, but we believe there may have been a shift in the soil beneath the foundation that resulted in the expansion of this crack, the dramatic expansion of this crack."
The U.S. government has recently allocated funds for the preservation of the Federal Hall structure.
But the National Parks Conservation Association, a private advocacy group, has placed the site on its list of 10 most endangered national parks. The group says additional funding is needed to protect historic documents and exhibits, and present the monument's legacy to the public through educational materials and experts.
Other monuments on the list are Big Bend National Park in the U.S. state of Texas, the Everglades National Park in Florida, Glacier National Parks in Montana and Alaska, Yellowstone National Park and the popular Great Smoky Mountains.
The conservation group's president, Tom Kiernan, says the national parks and their wildlife are threatened by air pollution, oil drilling and global warming.
"Our national parks are a litmus test for how we do in taking care of the environment and our natural and cultural heritage of this country," he said. "And, unfortunately, this list of 10 that we're announcing today shows that we are not yet passing that litmus test. They suffer from one or all of three major problems. Inadequate funding, misuse or polluted air."
But, he says, there is some good news. In the last year, the group has removed six national parks from its endangered list.