Climb a steep hill in 90 seconds on the second-oldest urban subway in the world.

Five sultans and their families rest in eternal splendor, teeming with overlooked beauty and drama.

This remarkably well-preserved Egyptian plinth is pretty well traveled for a giant piece of stone.

A marvel of Byzantine engineering under the streets of Istanbul.

With over 10,000 lights, this engineering marvel lights up the city after dark.

This extraordinary, multi-pillared monument depicts the fascinating history of Georgia.

A cluster of historic bathhouses built on the famed hot springs that gave the Georgian capital its name.

The charmingly disheveled clock tower of Tbilisi's puppet theater.

This mysterious but iconic tapered tower appears in many Azeri fairytales and legends.

The building's fluid, wavelike walls are a true feat of architectural ingenuity.

A unique museum dedicated to culture and artistry of carpet weaving.

A high-octane shrine to the greatest Texans who ever lived.

Locals dubbed it the "Owl Building" because of its bird-like appearance.

Roadside Americana, fairy tale characters, and Austin quirkiness come together at this magical course in the heart of Texas' capital city.

This simple frog painting created by musician Daniel Johnston embodies the spirit of Austin.

A trio of colossal statues spread across a Dallas neighborhood chart the emergence of a giant robot born of a locomotive and spilled gin.

This downtown Dallas art installation is always on the lookout.

A serene temple with stunning stained glass hides in downtown Dallas.

A historic, century-old house plopped along the perimeter of Houston's ballpark.

The largest underground pedestrian tunnel system in the U.S. mostly caters to the people working in the offices above, but provides a great, air-conditioned way to traverse the city.

A 90-year-old underground water reservoir offers a more industrial kind of tranquility.

One of the oldest colonial buildings still standing in South America.

One of South America's most exclusive resorts has a storied history dating back to World War II.

This giant power line tower is a robot that can express its moods in neon.