If you can look past the nearby sewer pipes, this urban sinkhole grotto is a mini-paradise.

A contemporary fresco movement illustrates the region's rich history.

This mesmerizing kinetic sculpture blossoms endlessly in the breeze.

A historic Montreal market that was the city's agricultural hub for over century.

The way these carnivorous dinosaurs are posed is an homage to a classic work of paleoart.

The fastest transatlantic ocean liner sat abandoned in a Philadelphia shipyard for decades.

This overlooked courtyard and museum celebrate Benjamin Franklin's life and achievements.

This elaborate towering structure was once famed for its revolutionary height.

The origin of this mechanical boy was a mystery until he revealed his maker by writing it in perfect cursive.

A daily replay of the experiment that proved the rotation of the Earth.

Tour the dark and beloved poet's former cobwebbed basement, which may have inspired "The Black Cat."

Yo, Adrian!

A hugely vast Irish landscape of barren rock that stretches for miles.

This statue celebrating everyday life in Dublin has a few unsavory nicknames.

The gorgeous library at Trinity College is home to remarkable treasures of Irish identity.

The house where the writer spent his formative years.

The 19th-century pharmacy (now a used bookstore) was featured in James Joyce’s "Ulysses," and has changed very little to this day.

This Neolithic passage tomb forms part of a World Heritage Site.

Every hour the doors open to reenact the legend of the heroic mayor who saved his town by drinking a gallon of wine.

Horrifically creative torture devices and shame punishments line the walls of this chilling museum.

A small but immensely extravagant palace built by the "Night King."

The fairy tale castle of the “fairy-tale king,” this was also the inspiration for Disney’s “Sleeping Beauty.”

A unique bridge with an equally unique view.

The bomb-ravaged remains of of a colossal Neptune.