The only royal palace on U.S. soil has been a territorial capitol, a military headquarters, and a prison for a queen.

This museum of Hawaiian and Polynesian culture is the legacy of the last descendant of the Kamehameha Dynasty.

Hide from the tourist hordes in these relatively unknown, and unguarded lava caves.

Football field-sized microalgae production tanks on the Hawaiian coast create a stunning view from space.

These ancient sacred grounds granted amnesty to those who managed to reach them.

This black shoreline is made up of exploded lava particles.

The world's brightest bioluminescent bay.

A massive underwater sinkhole made famous by Jacques Cousteau.

A public urinal so pretty, it was declared a national monument.

A beer pipeline runs beneath Bruges.

Explore 400,000 years of humans' "battle against darkness" in this offbeat but thorough lamp museum.

Made of giant chains and hung with shackles, this iron cross honors those unknowns who perished under American slavery.

They sort through millions of dollars worth of diplomatic gifts on behalf of the government.

The institution is sitting on a goldmine of 21,000 paints, varnishes, pigments, and primers preserved for posterity.

The most accurate timepiece in the world.

A cavernous three-story, 43,800-square-foot basement that was forgotten about for 60 years.

Not truly a ship nor a building, the Navy's first and last "landship" is now abandoned due to clerical issues.

Seemingly unremarkable items like empty sushi trays, chef hats, and freshness stickers are being preserved so future generations can look back on this beloved cultural import.

When it opened during the final years of the embargo, all the drinks and cigars were free.

The winding route passes through an enclosed alleyway, two tunnels, and leads to the White House basement.

Fittingly, America's museum of architecture is itself a magnificently designed old building.

A painfully obvious spy house sits right across the street from the Russian Embassy.

Enormous piles of historically significant stones, dumped by Congress in a forest, and abandoned for 60 years.

A tiny piece of the Moon is embedded in this stained glass masterpiece.