It's not the metro station itself, which is only about 30 years old, that warrants an entry here. But descend to Mustek's lower escalators and you'll see the illuminated stone remains of what was once a bridge that connected the fortifications of Prague's Old and New Towns. In Czech, mustek means "little bridge," but the ancient span isn't the only medieval remains that modern excavators discovered. Metro workers had to be inoculated when they uncovered viable tuberculosis bacteria, which had lain here dormant, encased in horse excrement, since the Middle Ages.

Na Príkope, the pedestrian street above Mustek metro station, literally translates as "on the moat," a reminder that the street was built on top of a river that separated the walls of Staré Mesto and Nové Mesto. In 1760, it was filled in. The street follows the line of the old fortifications all the way down to the Gothic Powder Tower at námestí Republiky.