Hotel Puerta America - which features work on different floors from some of the most high-profile architects - was opened this morning.
Among the world-famous stars featured at the Central Madrid hotel are five Brits - Zaha Hadid, David Chipperfield, John Pawson, Norman Foster and Kathryn Findlay.
And from abroad, there's also work from Jean Nouvel and Richard Gluckman on show.
Anton Iraculis, the Group's Chairman, said this morning at the opening: 'We at Hoteles Silken feel a great sense of pride and satisfaction at having completed this product: a dream come true for many people who believed in the added value of this new hotel.
'Our aim is to now convey to our guests the feeling that they are in a truly unique place, because of the surroundings and the treatment they receive,' Iraculis added.