Deep under Manhattan is the largest construction project in city history. So far, the project has taken the lives of 23 workers, or "a man a mile."

Spanish architects used seized Muslim gravestones to rebuild parts of the fortress.

A museum dedicated to the centuries-old cave dwellings that housed marginalized communities on the outskirts of the former capital of Muslim Spain.

An eerie collection of the surviving structures from a past celebration of the future.

A monument to one of the greatest matadors of all time.

The world's largest wooden structure.

Its appearance in "Game of Thrones" may spur on the long-awaited restoration of this medieval shipyard.

This elaborate tunnel is the first structure composed of cast concrete in the United States.

A tree that grows parallel to the ground was declared Brooklyn's "crowning curio" by the poet who saved it.

You can still ride this 100-year-old work of art in Brooklyn's largest public park.

Sniff the Titan Arum's rotting flesh.

This secluded ruin was once a home for exotic plants.

This striking arch, one of the first architectural elements constructed in Prospect Park, was recently restored to its original glory.

This metal eagle one of the final remnants of a newspaper that wanted to keep Brooklyn to Brooklyn.

This city park was once a lookout point for George Washington’s army during the Battle of Brooklyn in 1776.

Underneath the bustling city streets, a hydroponic farm grows unique herbs in an urban oasis.

This enormous banquet-themed artwork honors over 1,000 notable women throughout history.

Kings Cross Station pays tribute to its role in Britain's best-selling book series.

This ornate Victorian marketplace was the setting for Diagon Alley and the Leaky Cauldron in the first ‘Harry Potter’ film.

The commemorative stone column conceals a secret laboratory.

This one has sailed five times as far as Sir Francis Drake's famous ship.

Lie in a hammock where George Washington stood.

Blighted Irish field and the ruins of a 19th-century cottage on the edge of urban Manhattan.

This historic building housed the surviving crew members of the Titanic, who were left destitute after the wreck.