Golden Gate Park's historic collection of plants.

This concrete tangle of square pipes has stood as a proud thorn in the city's side since the '70s.

The last remaining relic of San Francisco's glittering 1915 Panama Pacific Exposition.

Staircase winds down the side of Telegraph Hill through gardens, wild parrots flying overhead.

San Francisco's newly reopened hands-on science museum.

The seawater playground of gilded-era San Francisco burned to the ground in 1966.

A favorite haunt of dinosaur loving children and hallucinogen loving hippies alike.

Olfactory delights in San Francisco's Botanical Gardens.

Relics of the 1894 Midwinter Exposition continue to delight visitors today.

Carnivorous plants, medieval aphrodisiacs, and the largest original wood structure glass conservatory in the western hemisphere.

In all of the 29 years it was in operation, no prisoners ever escaped successfully... or so they claim.

A jaw-dropping brutalist space church seems to have crash-landed in the middle of America.

This quirky roadside attraction provides insight into Minnesota's logging history.

A little-known memorial to servicemen and nurses killed in the line of duty during the First World War.

Sleepy Minneapolis block beats Guinness Record for most churches on one city block.

The oldest remaining frame residence in Minneapolis.

A hidden oasis in the heart of Minneapolis is also an Important Bird Area.

This old residential building was once the largest flour mill in the world.

One of the world's premier laboratories for hydraulic engineering research takes full advantage of the water's power.

Meet your friends, marry your true love, or tell your enemies to kiss your butt under this historic Pittsburgh timepiece.

A take-out restaurant that only serves cuisine from countries with which the United States is in conflict.

This quarter-mile tunnel under the Bluff in Pittsburgh bends at a 45-degree angle.

When oil was discovered just outside of Pittsburgh, the city became home to this regional stock market.

The last remnants of Fort Pitt also hold the distinction of being the oldest structure west of the Allegheny Mountains.