More than a million people visit Alcatraz Island every year to see the shuttered prison sitting in the San Francisco Bay, made famous by Clint Eastwood in the movie about the great escape of three prisoners in the early 1960s.

But these days, the prison, first opened to the public in October 1973, has been showing wear and tear, and some buildings needed new roofs, stabilizing and paint.

After more than a year of work, the National Park Service on Wednesday pulled the tarps off upgrades at Alcatraz, showing off $3 million in improvements to the sally port, guardhouse, library, schoolhouse and other historic areas.

"As we know, in this (guardhouse complex) things need to be seismically stabilized. This is an area that wasn't. Since every visitor comes in this direction, we want to make sure it's safe," said Chris Lehnertz, superintendent of Golden Gate National Recreation Area.

On Wednesday, park service officials used giant scissors to cut a wide red, white and blue ribbon held by volunteers dressed in Civil War-era military uniforms. Inside the sally port, a secure controlled entryway, they pulled down a large plastic tarp revealing sweeping views of the San Francisco Bay that had been blocked by a boathouse that was torn down as part of the restoration project.

"The sally port here on Alcatraz is really the entry point that reveals the layers of history that are preserved here on Alcatraz," said Lehnertz. "This is the original structure on the island. This is the most historic site on the island, the entrance to the experience that visitors see today."

In addition, the historic cannon port embrasure located in the east guard room has been restored to its original condition.

Other historic features that have not been visible for decades, such as the building's original entrance sign, "Alcatraces 1857," have been fully exposed and can now be seen by all visitors passing through the gate.

The island was originally named "Isla de los Alcatraces" — Island of the Pelicans — by Spanish explorer Lt. Juan Manuel de Ayala because the rugged rock was home to many sea birds. The name was later shortened and changed.

Visitors were first allowed on the island in the fall of 1973, and that first year more than 50,000 people came to see the closed prison. About 1.3 million people visit the island each year.

National Park Service historian Stephen Haller said now some of the earliest construction can be seen.

"You can see the earlier spelling 'Alcatraces island 1857,' which is when construction began," he said.

But it was the June 1962 Alcatraz escape that really put the place on the map. On the night of June 11 or early morning of June 12, inmates Clarence Anglin, John Anglin and Frank Morris tucked papier-mache heads into their beds, broke out of the main prison building through an unused utility corridor and floated away on a makeshift raft. Neither the inmates nor their bodies have ever been found. In 1979, Eastwood starred in the movie "Escape From Alcatraz" portraying Morris.