A stone slab in Madrid marks the point from which the distances of Spain's national roads are measured.

Elaborately carved to showcase the glorious wealth that the age of exploration brought to the Portuguese empire.

Sip cherry liqueur at a bar dating back to 1840.

One of the smallest bookstores on the planet.

Feast on buckets of garlicky snails.

Eat the ultimate iteration of Portugal's most beloved pastry.

An early Portuguese serial killer's head is alarmingly well preserved in a jar at the University of Lisbon.

The spiral staircase hidden inside this giant Parisian column was likely built for Catherine de Medici's astrologer.

An overlooked marble is the only surviving in-place 18th century example of the measurement that changed how we define distance.

The water-powered carriages are long gone, but for over a century this funicular railway has been the fastest route to the highest point in Paris.