Several moments in Boston’s storied past are a few of the weirder anecdotes in Northeast United States history. In 1919 a molasses tank burst on a blistering North End day, killing 21 and injuring 150. During the 19th century, surgeries were conducted before crowds at Massachusetts General Hospital. Dubbed the “Ether Dome,” the lesser known site has become the city’s strangest historic landmark.

Still located at MGH, the Ether Dome began as an medical theater between 1821 and 1867. Surgeons would perform operations before a regularly packed group of curious onlookers—a medical Coliseum. This was before the advent of anesthesias; the challenge and reason for spectators was to see how quickly doctors could amputate a limb. Scottish surgeon Robert Liston was world renowned in the 19th century for his ability to saw off a leg in under three minutes.

During this time, ether was primarily used by socialites as a giggle-inducing narcotic. The only pain relief patients were offered was a chug of whiskey or a club to the head—a knockout blow. This was practiced until 1846 when Edward Abbott received ether vapors before a tumor was removed in his neck. A stunned audience observed William Morton administer the drug and John Warren work on the unresponsive subject. Abbott reported no pain and medical history was made.

The Ether Dome is available to public view when it’s not hosting meetings and lectures. As was popular during the Antebellum era, the amphitheater was designed in a Greek-revival style. Its white walls, wooden floors, and staggering natural light—on a cloudless day—give the Ether Dome an antique aesthetic, transporting visitors to an earlier age. Horror fanatics will appreciate its unsettling vibe. Art enthusiasts will marvel at a 19-century period oil painting made during a reenactment from 2000.

Also on display are early surgical tools, a complete skeleton, and an authentic mummy of Padihershef. The Egyptian artifact was donated to the hospital in 1823, and is on exhibit in its full, painted coffin. Anyone who has been to the Mutter Museum in Philadelphia can expect a similar experience.

The Ether Dome is open Monday through Friday between 9:00 a.m. and 5:00 p.m. Admission is free and the museum is easily accessible from the Red Line Charles/MGH T stop. The address is 55 Fruit St., Boston, MA 02114.