The last bastion of Roman presence north of the Alps looms over a German town.

The building features one of the last remaining free-floating spiral grand staircases in the U.S.

Three and a half miles of cliffs, rocky beaches, Gilded Age mansions and 40 Steps to nowhere in particular.

This Rhode Island mansion was a stand-in for the exteriors of Collinwood in the original "Dark Shadows" series.

An ode to Japanese artist Hokusai, with a bit of a comical twist.

One of Antoni Gaudí's least-visited works, an homage to Catalan patrimony that mixes neo-Gothic with Modernista forms.

Occupied for six centuries by Franciscan Order nuns, this monastery is an amazing ode to Catalán Gothic architecture.

This stunning iron gate designed by Modernist architect Antoni Gaudí is filled with mythic symbolism.

A cemetery in Barcelona's Poblenou district is home to this touching funerary statue, which depicts death in the form of a winged skeleton.

A Norwegian-born sculptor created these soaring guardian angels at the entrance to Hoover Dam.

These markers are used to document elevation changes around the famed dam.

Public opinion is still divided on this enormous sculpture in front of Baltimore's Penn Station.

Once part of a dam servicing an early 19th century grist mill, the tucked-way falls are a tricky-to-find urban oasis.

A restaurant and observation deck built in a unique broadcasting antenna.

Outside the Department of Transportation, a collection of artifacts honors the history of how we get around.

This statue of one of baseball’s greatest pitchers looks like something out of a sci-fi horror movie.

The "Sultan of Swat" once attended a school at the site of this baseball field.

This colorful gate stands as an entrance to the walled city of Old San Juan.

The ruins of the first Spanish settlement in Puerto Rico.

The now-quiet remains of coastal artillery defenses that were used in both World Wars.

This lighthouse was crafted as penitence for the theft of wine bound for a monastery.

The UK's oldest theme park slowly slips away.

Home to an endangered salamander, a full moon celebration, and a large spring-fed outdoor swimming pool.

The metal leaves on this tree are engraved with the names of Holocaust victims.