: The term is occasionally confused with "sanatoriums," which are common in Central and Eastern Europe. These are medical or recreational spa facilities (such as those in Karlovy Vary) that offer treatments like massage, hydrotherapy, and light therapy.
A solarium is designed for healing: light therapy, vitamin D, warmth. In the show’s fictional universe, the Czech government weaponized this. They built —a "quantum solarium" that used concentrated radiation to "erase undesirable memories" from dissidents. czech solarium 13