This Industrial Age architectural and engineering gem helps visitors and residents alike traverse Lisbon, “The City of Seven Hills.”

The stunning interior of this Gothic church is covered in ornate gold details.

This unreal Portuguese palace looks as though it's made from a pile of different castles.

One of Serbia's oldest luxury hotels and a nostalgic echo to Yugoslavia in the state's former capital.

A bronze sculpture honoring a famous Serbian writer and a character from his novel.

A retro Yugoslav congress, cultural, and business hall built in the 1970s, with an iconic world clock.

This small bronze pyramid marks the center of Belgrade, but some say it is a Masonic symbol.

This statue of the famed author, actor, and journalist is made entirely of screw-nuts.

Two buildings named after their windows that make it look like a sea of television sets plastered to a wall.

Belgrade’s oldest restaurant has a rather unusual name.

An Art Deco Icarus statue adorns this abandoned gem of Yugoslav Modernist architecture.

Backwards hour and minute hands and a timing mechanism that fluctuates with the temperature led to this clock tower's local nickname.

This statue of a goat in boots is meant to represent the European Union.

This striking, historic hotel has major Wes Anderson movie energy.

The unusual sculptures are believed to be powerful political symbols.

A towering spire in the fortress of Kalemegdan honors the victorious armies of Serbia during their struggles against the Ottoman Empire.

Memorial to the victims of the Holocaust in Serbia.

This feat of Brutalist architecture is also known as the Three Sisters.

Different sections of the Zemun Fortress were built in the 14th and 15th century as a response to the advance of the Ottoman Empire.

A small memorial to a deadly night in Serbia that shook the world before it was swept under the rug.

A museum dedicated to the former country.

Religious perseverance and cultural coexistence manifest in an architectural gem that multiple wars couldn't topple.

Ride in 1960s style on the private luxury train Marshal Josip Tito used to travel around Yugoslavia.

Destroyed Serbian army headquarters sits half crumbled in a largely revitalized Belgrade.