9 iconic landmarks in the US that are falling apart

• Travel hubs like Penn Station and LaGuardia Airport in New York are in need of serious improvements.
• Mount Rushmore is full of cracks and requires constant maintenance.
• There are many other iconic landmarks in the US that are falling apart.

The US is full of important historical landmarks and iconic pieces of infrastructure. But many of those sites are beginning to show their age. 

Here are 9 landmarks around the US that are falling apart.

Montauk Lighthouse — Montauk, NY

Montauk Lighthouse is a National Historic Landmark as the oldest lighthouse in the state of New York. Its construction was authorized by none other than President George Washington in 1792.

Over the past 200 years, 200 feet of Montauk Point's coast has been eroded by the Atlantic Ocean. The lighthouse now sits only about 75 feet away from the edge of the bluff. Some have proposed moving the structure further back or reinforcing the cliff it sits on before it plummets into the sea, according to the New York Times.

The J. Edgar Hoover FBI Building — Washington, DC

FBI officials have been pushing for new headquarters for a decade, according to The Washington Post. Completed in 1975 by President Gerald Ford, the building is now a mess of cracked concrete, outdated building systems, and haphazard office spaces in storage areas.

According to a 2011 report from the Government Accountability Office, only 53% of the building's space is actually usable.

Penn Station — New York, NY

Bloomberg called Penn Station "the most awful transit center in America" due to its crumbling infrastructure. 

The original Penn Station was a masterpiece of neoclassical architecture that stood from 1910 until 1963, when it was demolished to make way for Madison Square Garden. Now completely underground, it's the busiest travel hub in the Western world — busier than Heathrow Airport in London and Newark, La Guardia, and Kennedy airports in the New York City metro area combined. But with train derailments, sewage water leaks, and underground tunnels operating on borrowed time, Penn Station is barely functioning.