A lawyer killed during a lightning strike. A celebrated American playwright. A suicidal businessman. These are just a few of the restless spirits that are rumored to haunt some of Boston's old buildings. Even if you're on the fence about the possibility of ghosts, learning about these nine haunted hotspots might make you wonder just what caused that bump in the night.

1. Fort Warren

The chill seeps into your bones as you stand inside Fort Warren. You catch sight of something black, out of the corner of your eye. Is it just a shadow darkening this historic structure, or have you glimpsed the infamous Lady in Black?

Fort Warren is located on Georges Island – one of the Harbor Islands. Constructed in 1861, it remained operational through World War II. One of the fort’s uses was as a jail for captured Confederate soldiers. The story goes that the Lady in Black was Mrs. Lanier, the wife of an incarcerated soldier. She rowed to the island, dressed as a man. While she was trying to free her husband and some of the other inmates, the guards realized that an escape attempt was in progress. During a struggle with an officer, Mrs. Lanier’s gun went off, fatally shooting her own husband. The story goes that she was later hung as a spy. Her final request was to be dressed as a woman for her execution. The only available clothing was a set of black robes, which explains how rumors of a "Lady in Black" were born.

Although it’s unclear if such a woman ever existed, there have been numerous sightings over the years. So, there's something spooky going on at Fort Warren…

2. Granary Burying Ground

Aside from the creepy headstones at this burial ground, where the likes of Sam Adams, Paul Revere, and John Hancock were laid to rest, orbs and ghostly images regularly appear in photos captured here. It’s considered a hotspot of paranormal activity in Boston.

One of the restless spirits is thought to be the ghost of lawyer and tax collector James Otis Jr. He supposedly expressed a desire to be killed by a lightning strike… which is actually how he died.

3. Cutler Majestic Theatre

As far as ghosts go, those haunting this theatre appear to be of the friendly, "Casper" variety. If you’re stuck with spirits, you could do far worse than host ones that keep unused theatre seats from getting dusty.

One of the ghosts is said to belong to a young girl who appreciates any gifts left for her... at least that’s assumed to be the case since the knickknacks vanish. Heck, this spectral lot would probably even write a good online review for the theatre!

4. Shelton Hall (now Kilachand Hall), BU

Abrupt changes in temperature. Random knocking. An elevator that appears to have a will of its own. These seem like a great way for students to scare each other late at night. However, before Shelton Hall was a Boston University hall of residence, it served as a Sheraton Hotel. In 1953, playwright Eugene O’Neill checked into Room 401 and never checked out. It is supposed to be his restless ghost that haunts the building.

5. USS Salem

You might expect rumors of unquiet spirits to plague a military ship that had seen action; however, the USS Salem was only in service for a decade between the 1940s and 1950s. It never saw combat. So why all the ghost sightings?

6. Hooper Lee Nichols House

This house, located in Cambridge, dates back to 1685 and is now home to the Cambridge Historical Society. You probably think that not much happens in a residence devoted to the past. Well, the mysterious voices heard here suggest otherwise. Some people attribute the sounds to a ghostly card game that is being played by the spirits of five Hessians… in perpetuity. That’s a long time to have a bad hand!

7. Boylston Street Station

In March 1897, tragedy struck at the corner of Boylston Street and Tremont Street. A giant gas explosion shook the intersection, where carriages and streetcars were traveling. One of the streetcars was blown right off its tracks; this accident claimed the lives of six people, with 60 more sustaining injuries.

At the time, the public worried about the safety of the new subway and speculated about whether digging was somehow responsible - construction on the T-station under the intersection was in full swing when the incident occurred. However, the accident was due to a faulty gas pipe. So why would the Boylston Street Station be haunted? Well, the explosion took place directly overhead and the spirits of the victims are thought to have remained in the tunnels.

8. Omni Parker House Hotel

Customer service transitions from attentive to downright creepy when the proprietor of an establishment sticks around after his death to ensure guest satisfaction! One of the ghosts spied at the Omni Parker Hotel is believed to belong to the deceased owner, Harvey Parker. If you stay here, be sure to stick the "do not disturb" sign on your door!

During his life, Charles Dickens spent time at the hotel. Some guests who dare to peek into the mirror on the mezzanine level claim to have seen the author looking back at them.

9. Charlesgate Hotel

The architect who designed this Romanesque Revival-style building is among those who died here. J. Pickering Putnam passed away inside his building in 1917.

In 1908, a depressed businessman committed suicide by shooting himself in the Charlesgate, and it is thought to be his spirit that causes weird happenings. People claim to have seen ghostly horses, mysterious fog and have experienced electronics that turn on and off on their own. The Charlesgate has been used as dorms for two different colleges and has since been turned into condominiums.

Have you spent time in any of these places? If so, did you experience anything to suggest these buildings are haunted? Let us know in the comments.