Pennsylvanian mass grave and possibly mass murder.

This meticulously extracted nervous system allegedly came from a 19th-century custodian who donated her body to science.

Surrounded by industrial sprawl, a small monument marks the site of William Penn's first landing in Pennsylvania.

North America's oldest quarantine facility was built in response to Philadelphia's 1793 yellow fever outbreak.

One of the oldest log cabins in America is one of the last of its kind this historic Swedish dwelling remains a piece of living history.

The corporeal remains of Napoleon III's dentist rest under this 15-story obelisk.

This 15-foot tall obelisk commemorating the Philadelphia-Baltimore railroad connection sat neglected for over a century.

Richard Luke Concanen never set foot on American soil.

Vice President Humphrey's final resting place is tucked away in this cemetery along with a few other notable figures.

The oldest surviving presidential residence in the United States.

One of the greatest boxers and humanitarians to ever live chose his hometown as his final resting place.

A local road runs around a memorial to a teenager who died in 1860.

The San Andreas Fault spectacularly offsets this creek.

This roadside stand packs 300-plus varieties of tomatoes, from "Maiden's Fire" to "Kaleidoscopic Jewel."

The easiest way to the highest point in Wyoming is only accessible via one hefty fee.

Pennsylvania's highest point is spotted with boulders which were pushed to the surface by nothing but cold.

Hundreds of antiquated typewriters and office machinery show the technological evolution of business.

The highest point in Delaware is located under a trailer so this marker across the street will have to do.

Descendants of this colonial Pennsylvania family still travel from far and wide to visit the 300-year-old home of their Quaker ancestors.

The final resting place of up to 6,000 Confederate soldiers, the largest mass grave in the Western Hemisphere.

The largest cemetery in Louisville is the final resting place of Col. Sanders and Muhammad Ali.

This magnificent Cincinnati graveyard is also a popular public park.

A historic arboretum and non-conformist, non-denominational park cemetery.

A 12th-century fortress containing some of Berlin's oldest buildings.