This project resets on two principles: The Museum should be part of the natural- artificial landscape of Madrid´s western edge, while preserves the open and public nature of La Almudena Square and the views of the gardens beneath. The Museum, in its linear structure as an inhabited retaining wall, tries to reduce the objective (physical) and subjective (collective unconscious) environmental impact on the monumental plinth of the Royal Palace. The aim is to have an invisible building from La Almudena Square by occupying a buried space that is yet to exist. A compact building, which uses the materials of the Royal Palace and its dignified construction as a feature, with a modern layout, heavy yet light, opaque yet transparent. The three exhibition levels, hold three differentiated collections, organized as a warehouse of 110x16 meters, flanked by the remains of the Arab wall to the east and a monumental lattice of massive granite pillars open to the west above Campo del Moro Royal Gardens. The Museum of Royal Collections is a plinth for the Palace, a frame for views of the gardens and the interior features. The most important part already exist; our job is to make it visible.