The site of one of history's most indelible and horrific tragedies.

Mysterious rocks that ring musically when struck.

One man's lifelong obsession with death.

This colonial mansion has been home to a staggering number of American historic figures.

This local gem houses the largest collection of pre-Raphaelite paintings outside of the U.K.

This splendid Versailles-inspired mansion has the largest French-style formal gardens in North America.

This might just be the TARDIS of bookstores.

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

This Philly landmark has a giant butterfly pavilion, three floors of insect displays, and withstood a $40,000 heist.

Frank Lloyd Wright built this suburban synagogue late in life, but it stands among his most iconic masterpieces.

The final resting place of one of the United States's greatest poets.

This Philly cemetery is the eternal home of many famous area residents, including Rocky Balboa's wife.

A rare view of a preserved Victorian science museum.

This elaborate towering structure was once famed for its revolutionary height.

This little-known collection holds everything from "Dracula" notes, to the manuscript of "Ulysses," to the forged works of Shakespeare.