From Ford's Theatre in Washington to the Statue of Liberty National Monument in New York, posted signs informed visitors that some of the nation's most historically significant landmarks were closed for business for the time being.
While the Trump administration has pledged to keep the parks as open and accessible as possible, the National Parks Conservation Association estimates that a third of the country's national park sites are completely closed, including many sites contained within buildings and other structures that can be locked and secured.
Those that remain open are likely operating with limited staff. Facilities like full-service bathrooms, museums and visitor centers are closed at many parks.
A sign posted at Rocky Mountain National Park warned visitors that the National Park Service is unable to fully staff the property and cautioned visitors to proceed with extreme caution.
But in some cases, the closures didn't stop tourists from sightseeing. Visitors could be seen lining up outside Philadelphia's Independence Hall to get a glimpse of the Liberty Bell through the window.
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