Inside Alcatraz Federal Penitentiary?

It's been 50 years to the day since Alcatraz closed its doors. On March 21, 1963, Alcatraz Federal Penitentiary, located outside San Francisco, closed due to economic and environmental issues. Notorious gangsters like Al Capone and James "Whitey" Bulger once walked the halls of the high security prison. Here, the last group of prisoners is handcuffed and led out of the prison. Take a peek inside Alcatraz on this anniversary ...

The No. 2 gun tower is pictured on the west side of Alcatraz in 1956. To the right, the recreation yard can be seen.

The three Alcatraz escapees slipped through this air vent during their great escape on June 12, 1952.

The main cell block that once housed the most infamous gangsters in American history is pictured on March 13, 1956.

Alcatraz Federal Penitentiary still stands in California and is open for tours.

Pictured here in the 1970s, Alcatraz Federal Penitentiary and the island it stands on can be seen from above.

Well, it was the summer of 69! It was estimated that over 120 Native Americans occupied Alcatraz from Nov. 1969 until June 1971. The Occupation of Alcatraz ended after the American government cut off all power and water to the island in 1971.

Gangster Mickey Cohen was sentenced to prison in Alcatraz in 1961 for tax evasion. The mobster spent 4 months locked up in "The Rock." Here, Cohen walks free onto a San Francisco Pier on Oct. 17, 1961.

The great escape from Alcatraz marked its 50th anniversary on June 12, 2012. Five decades earlier, John and Clarence Anglin and Frank Morris disappeared from the high security prison. Though they were said to have drowned in the San Francisco Bay, their bodies were never found. Here, a picture released by the prison shows the dummy head (l.) that was used by John Anglin to fool prison guards into thinking he was in bed.

This might be enough to give someone the creeps! The operating room of Alcatraz is pictured here on March 13, 1956.

Known as "The Rock", Alcatraz Island in San Francisco Bay became a national recreation area in 1972 and a National Historic Landmark in 1986. Here, a rainbow spreads over the island on Nov. 25, 1951.

Another great prison escape occurred on May 2, 1946. During the Battle of Alcatraz, prisoner Bernard Coy climbed up the bars of the gun gallery (pictured here) and knocked out a prison guard to begin the bloody, yet botched, escape attempt. Two guards and three prisoners, including Coy, were killed in the scuffle that lasted two days.

John Paul Chase (c.), companion of "Baby Face" Nelson, is seen on March 28, 1935 being escorted out of Chicago in the company of federal marshals. Chase was sentenced to life in prison at Alcatraz for the slaying of federal agent Samuel Cowley.

In 1934, San Francisco Police Chief William J. Quinn (l.-r.), Warden James A. Johnson, U.S. Attorney General Homer S. Cummings, and San Francisco Mayor Angelo Rossi inspect a cell block in the main building of Alcatraz. "The Rock" was fully operational from 1934 until its closing in 1963.

You can't hide when you're linked to the infamous Al Capone! Mae Capone, wife of gangster Al Capone, was snapped on her way to visit her husband at Alcatraz on March 1, 1936.

Gangster Al Capone is seen here outside the Chicago Federal Courthouse in October 1931. Capone would be sentenced to prison and serve 7 years in Alcatraz until his release in 1939.