The history of the tea trade is told in bas-relief on this historic pair of Boston doors.

The site of one of the strangest disasters in history—a wave of deadly molasses traveling at 35 mph.

The American Revolution was galvanized into serious action due to the tragic clash with British soldiers that occurred at this location.

Macabre headstones carved with winged skulls, dancing skeletons, and pithy reminders of impending death.

The Boston square dedicated to the dark poet who was born nearby.

A morbid secret lies hidden within the beautiful walls of the Boston Athenaeum.

Two thousand artifacts from around the world collected by one woman who loved to travel.

An enormous, inside-out glass globe built in 1935.

The best preserved Paleochristian basilica in Rome hides a number of oddities and secrets.

One of Catholicism's four major basilicas has a series of papal portraits that are said to predict the end of the world.

A treasure trove of Renaissance-era funerary art in a Roman church built on top of Nero's grave.

This historic recreationist school churns out warriors that may very well have had a fighting chance in Rome's pits of the day.

The martyr's wax-enhanced skeletal remains lie preserved in a glass case in the Santa Maria della Vittoria in Rome.

Installed in an act of one-upsmanship, the annual sundial in this church is also a symbolic victory for the Gregorian calendar.

The engineering wonder and pleasure dome of a much-maligned emperor still holds undiscovered secrets.