I'll be covering a portion of Alcatraz as it's always has been a fascinating place of alleged hauntings, ghost stories and paranormal-happenings.
Located about 1.5 miles from the shores of San Francisco, California lays "The Rock" as it was often referred to as. The official-name is, of course, Alcatraz.
Alcatraz had served a few different purposes in its time(currently it's a museum) but it once took the role of being: a lighthouse, a military fortification during the Civil War, a military prison and most popularly a federal prison until 1963. It housed some of the most notorious-criminals of the time including: Al Capone, (the birdman of Alcatraz); Robert Franklin Stroud, Alvin Karpris, James "Whitey Bulger and George "Machine Gun" Kelly.
As with any maximum-security prison, death was present at times within the walls of The Rock, either from shankings, guard-attacks, escape-attempts, suicides, etc...and so begins the rumors of Haunted Alcatraz.
It's believed that Alcatraz contains many spirits that have once inhabited the prison, some feel that the spirits located within are not able to venture anywhere else being that the facility is located on an island, surrounded by water. I don't know whether this makes the haunts reported at Alcatraz any more credible or likely to happen, but it's a plausible theory.
During the day, Alcatraz is a popular tourist-attraction, filled with many people at any given business-hour, scouring through the prison, buying gifts at the gift-shop. However, at night, the atmosphere changes to a dark, stale, dingy facility of eeriness, not witnessed by many.
Visitors, guards and even inmates have reported seeing, hearing, sensing, feeling and smelling things that were unexplainable. For instance: Guards on duty would occasionally smell smoke with no source of fire, unexplainable cold-spots in just certain areas of the prison, some even seeing the ghosts of past prison personnel , inmates and even further back, during Alcatraz's military days, apparitions in military-uniform.
A few interesting ghost stories:
Warden Johnston's Experience: Warden Johnston was well, the warden of Alcatraz from 1934-1948. During a tour with a group of guests the warden and those accompanying him, witnessed unexplainable sobs near an area they were in. Soon after they had all felt a very cold breeze whisk past their group.
Cell14D: This cell is said to always be colder than any other cell, many believe that the cell is a huge hot-spot for spiritual-activity. One guard even reported that it could be 70-degrees outside, and cells nearest to Cell14D would be nearly as warm as the 70-degree outside weather, but that Cell14D required a jacket if you were in there long enough, usually the cell had a sudden intensity within it as well.
A prisoner during the 1940's was holed up in Cell14D, who is rumored to have screamed throughout the night that something was in the cell with him, a creature, complete with evil, glowing eyes was killing him. Supposedly, the following morning the prisoner was found, in his cell, strangled to death. No one was ever held responsible. However, a guard the next day had accidentally included the dead prisoner during a head-count with assumptions that he'd seen the prisoner in line, but only for a few short seconds.
The A, B and C cell-blocks: Guests and inmates have reported hearing sobbing, moaning and crying in the A and b cell-blocks, while in cell-block C a medium had allegedly contacted the disruptive-spirit known as Butcher. Indicated through prison-records, it's documented that an inmate murdered Abie Maldowitz, a well known mob hitman known as Butcher.