Infrastructure

A forgotten relic from New York's bygone trolley system hides in plain sight under a bridge.

The now-abandoned tunnels were built for the transcontinental railroad on the route where the first wagon train entered California.

Once the world's largest reinforced concrete structure, this abandoned bridge now beckons urban explorers.

A giant concrete Brutalist water tower in suburban Johannesburg.

This beautiful defunct water tower adds a European flair to a traditional Japanese neighborhood.

These colossal desert barcodes have been fine-tuning spy satellites for decades.

An 18-mile-long tunnel for sewage waste will soon wind within the bowels of Washington, D.C.

The Netherlands is home to a bridge printed out of reinforced concrete.

Tile mosaics and quotes from Pablo Picasso add an artistic flair to these bus stop benches.

This "synagogue" is not what it seems to be.

One of few surviving standpipe water towers in the U.S.

At just 25 inches at its narrowest point, it's one of the tightest streets in the world.

This forgotten boat elevator was an engineering marvel in its heyday.

The ill-fated plan to reroute the Mississippi so that Union ships could bypass Confederate fortifications on the river bend.