A once grand hotel is being retaken by the wilderness it once capitalized on.

A celebration of capitalism in Midtown.

One of the last few places in Manhattan that employed a pneumatic systemic keeps it on display.

Whisper secrets in a busy station only to be heard on the other side of this acoustic arch.

Mysterious 500-year-old tapestries depict a unicorn hunt.

One of the Seven Wonders of the Modern World holds the world's tallest metal staircase.

A 98-room castle in the middle of Toronto that bankrupted a 19th century electricity multimillionaire.

A clear example of the process of erosion in action.

Nine limestone rock stacks on Australia's "Shipwreck Coast."

The colony of South Australia was proclaimed on a hot December day under a distinctively arched gum tree.

The largest collection of Indigenous Australian artifacts in the world, and the rare museum where wood-and-glass cabinets have trumped interactive exhibits.