A 140-year-old castle with underground caves hidden in San Francisco.

A psychedelic labyrinth on the San Francisco bay.

An artsy hidden staircase leads to breathtaking views of San Francisco.

A huge musical instrument played by the ocean.

A rare cluster of alien-like plants grows along a dusty highway.

South Africa's postal service began with a letter left in a boot beneath this tree.

“The oddest pub in South Africa,” inspired by a practical joke.

This small island off Lambert's Bay is home to more than 2,000 Cape gannets and is the only such breeding colony open to the public.

The haunting beauty of this little-visited wreck makes it a true hidden treasure.

Many generations ago, it was said that one could find celestial splendor in a lush meadow not far from this very marker according to the lore of the fictional world Kcymaerxthaere.

This historic observatory was established to keep shipwrecks from littering the Cape of Good Hope.

A sobering account of the vibrant multicultural neighborhood that was destroyed under apartheid.