Construction of Barcelona's iconic (but controversial) church is expected to be completed in 2026—a century after the death of its architect.

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

A mysterious chasm in the heart of the ancient Roman Forum, the Lacus Curtius was once believed to be a gateway to hell.

The last moments of the ill-fated Pompeiians, frozen forever in plaster.

The only visible reminders of an elaborate engineering project that kept the tower from reaching the tipping point.

An Orthodox church built by the Royal Family for the Russian community exiled to the French Riviera.

Historic medieval fortified city in southwest France.

The industrial architecture honors the laborers who brought the Exposition Universelle of 1900 to life.

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.

Twelve grave-faced marble angels guard the emperor's tomb at Les Invalides.

A popular shrine where the Blessed Virgin allegedly appeared in 1830, displaying a holy armchair and two incorruptible remains of Lady Saints.

This life-size replica of the Statue of Liberty's flame is also a tribute to Princess Diana by default.

Indents in the pavement are all that remain from a grisly death machine in Paris.

The ruins of a Duke's bucolic dream, where camels once roamed alongside "Dutch" windmills and faux-Italian vineyards.

The oldest stone house in Paris was built by its most famous alchemist.

In this Parisian garden's grotesque former life as a zoo it fed exotic animals to the bourgeois and put humans on exhibit.

This Paris art space celebrates the creativity and ingenuity that springs from abject poverty, especially in Africa.