"La Isabela", the spa where the story takes place, really existed beside the reservoir of Buendia (province of Guadalajara, Castilla-La Mancha, Spain). The health resort was built by Ferdinand VII in 1826 as Royal Site and for the first time it was created there an architectural project for leisure use, with the bourgeoisie and nobility as main users. After the revolution of 1868, the management of the spa ended up in private hands. It continued to operate, in decline until 1955, when the rising waters of the reservoir of Buendía left this historic site submerged under water.