Isaac E. Emerson, the father of the modern headache cure, had a flair for marketing. This 15-story tower was his magnum opus.

After graduating from the University of North Carolina, Emerson settled in Baltimore, where he developed his headache remedy in 1888. Bromo-Seltzer was one of the first antacids and, like the seltzers of today, was sold in pills to be dissolved in water.

Used to treat headaches, heartburn, indigestion, and—perhaps most commonly—hangovers, the wildly popular product swiftly made Emerson a fortune. (Part of the seltzer’s effectiveness was due to its heavy, no-longer-FDA-approved concentration of bromides, which are a class of sedatives in the tranquilizer family.)

Emerson was a savvy businessman in addition to a talented inventor, and understood the importance of advertising. He embraced print and radio promotions and used his company’s factory building (which has since become a fire station) as a conspicuous and permanent 3D billboard, erecting the Emerson Bromo-Seltzer Tower next to the building.

The tower’s main attraction is the massive clocktower, with a clock face on each of its four sides. Each is made of white glass and the numeral placements spell out B-R-O-M-O when read clockwise and S-E-L-T-Z-E-R when read counterclockwise. The clocktower was originally capped by a rotating, blue, 20-ton, 51-foot Bromo-Seltzer bottle. This flashy topper was removed in the 1920s, as it became clear that the base would be unable to support its weight.

In recent years, the tower has been repurposed as a collection of rental spaces and artist’s studios. The clocktower, with its expansive views of the city, is open for tours. The museum houses the largest cobalt blue glass bottles used to bottle the headache cure.