Sections of the iconic limestone columns have been left uncleaned as a reminder of the city's polluted past.

There aren't too many operational funiculars around, but Pittsburgh has two!

This secluded walking trail is a hidden gem of a Pittsburgh park.

This restored log building was one of the first toll booths for travelers along the Northern Turnpike.

This icon of the Atomic Age now lays dormant.

This beautiful stone arch bridge wasn't even expected to stand for one day, but people have been crossing it for centuries.

The universally beloved children's television figure is interred on a high hilltop in one of western Pennsylvania's oldest cemeteries.

Each step is a mere 4 inches tall, said to be measured by the stride of a woman wearing a hobble skirt.

The site of the little-known Pennsylvania battle that sparked the Seven Years' War.

A miniature golf course crafted inside the world's largest simulated cave.

This historic furnace was once used to produce cannonballs during the Civil War.