The third point of Madrid's museum 'Golden Triangle,' built almost entirely from one family's private collection — assembled across two generations and bought by Spain for around $350 million in 1993.
German industrialist Baron Heinrich Thyssen-Bornemisza began collecting Old Masters in the 1920s; his son, Baron Hans Heinrich, expanded it dramatically over the following decades until it became one of the most significant private art collections in the world, second in scale at the time only to the British royal collection. After negotiations with several countries, the Baron's Spanish wife, Carmen Cervera, helped steer the collection to Madrid — the Spanish government rented it in 1992, then bought the core 775-work collection outright a year later. The neoclassical Palacio de Villahermosa on the Paseo del Prado was renovated to house it, with the Baroness personally choosing the museum's distinctive salmon-pink interior walls.
Rather than a national collection built over centuries, the Thyssen is one collector's eye across roughly 800 works, spanning the 13th to the 20th century in a single continuous walk — Duccio and Van Eyck on one floor, Van Gogh, Kandinsky and Hopper a level up. It deliberately fills gaps the Prado and Reina Sofía don't cover as strongly, especially German Expressionism, Impressionism and the American landscape tradition.
2 hours covers the highlights; the collection is dense enough that a slow, complete visit can take half a day. Because it's smaller than the Prado, it's the easier of the two to actually finish in one visit.
The Prado, the Thyssen and the Reina Sofía sit within a 10-minute walk of each other along the Paseo del Prado — ambitious but genuinely possible to visit all three in a single (long) day if you prioritise ruthlessly in each.
Banco de España Metro station sits right outside; it's an easy add-on to a Prado or Retiro Park visit given the shared location.