The iconic wall that surrounds the Minnesota Correctional Facility-St. Cloud has a unique claim to fame.

“It’s the second longest continuous wall in the world, only behind the Great Wall of China,” Captain Mike Poppen said.

Opened in 1889 as the Minnesota State Reformatory for Men, inmates started assembling the wall brick-by-brick from granite found inside the prison quarry.

“This was put up with horsepower and by hand and not the advanced tools, hydraulics and lifts they have nowadays,” Poppen said.

After 11 years, the wall with 10 guard towers was completed in 1916.

“We are 22 feet high,” Poppen said. “We’re about 4 1/2 feet thick. It does go below ground quite a ways. It’s just over a mile and a half.”

The prison is listed on the National Register of Historic Places.