Places Mathias Van de Velde Wants to Go

This futuristic German spa allows visitors to float in a pool of salt water while zoning out to underwater techno.

A whimsical and twisted animatronic monster tour beneath the streets of Berlin.

Spiral alpine structure provides an alternative experience of viewing the Matterhorn.

A Swiss magician's vault of oddities.

This statue pays tribute to the iconic musician in the place where he recorded his final studio album.

Amsterdam's Red Light District leaves little to the imagination.

This massive mural by famed pop-artist Keith Haring was hidden for almost 30 years until its 2018 rediscovery.

This unattributed sculpture in Amsterdam is hiding in plain sight.

This 22-floor tower's Skydeck offers panoramic views of Amsterdam.

This museum is filled with an eclectic collection of unique inventions.

The only urban monument in the world designed by the great surrealist painter Salvador Dalí.

The morbid items in this small and hidden museum are not for the weak stomached.

This amazing abuela became a diehard metal fan late in life and an icon of Madrid's '80s rock scene.

Over two centuries old and counting, Madrid's massive botanical garden contains one of Europe's only desert environments.

An ancient Egyptian temple in the middle of Madrid, Spain.

Madrid's romantically ornate crystal palace has been offering shelter to plants and art for over a century.

The oldest restaurant in the world is this old-world Spanish eatery, still known for its suckling pig.

Grotto replete with mystical designs laid out in glued shell mosaics.

This old, abandoned hotel offers magnificent views.

A beach made of semi-precious green sand on the Big Island of Hawaiʻi.

Hide from the tourist hordes in these relatively unknown, and unguarded lava caves.

These picturesque Hawaiian falls are home to a rare species of fish that uses a special sucker to climb up cliffs.

A tunnel of hardened lava along Maui’s famous Road to Hana.

This black shoreline is made up of exploded lava particles.