The door of the birds is found in the House of Moro, so it is known both by the name of the family that acquired it and by the vain devoted to the birds as described below. After the completion of Antonio Gaudi's El Capricho, the Moro family, close relatives of Maximo Diaz de Quijano, were so fascinated by the unique work that they asked the great artist to design the front door to his house. The project preserved two sketches of the complex and the height of the building, which Joseph Rafolsin Francesco published in his architect's biography in 1929. The home building was not finished due to the economic collapse of the owner who was doing a business that went wrong in the theatre world. Only the basis of the structure and the lawn gate were made of masonry and had three openings, one for pedestrians, one for carriages and a round hole above the pedestrian door, which Gaudi called the "door of the birds".

This entrance is situated in Cotera in the Santa Lucia area next to the Hermitage. From this location, you can view the sea. This is a porthole through which vehicles can go through, a passage for individuals and a kind of a unique passage for the birds, completed in 1900. The construction consists of improperly arranged stone waste and traditional wall materials. The method used was to smash stone debris. They are smashed and assembled irregularly (this is the same technique that Trencadis uses with which Gaudi would beautify Park Güell). As with El Capricho, the edges are not used, but there are corrugated surfaces that give a rounded shape to all corners, and curved door volumes that give the doors a greater charm.

It is said that while Gaudi was walking along the beach in Comillas and he was designing the commissioned door with his stick in the sand, a flock of birds passed. Being a great lover of nature, he felt it is appropriate to add a step to the door... an entrance for birds. This is the reason why this door is known by the two names, that of Puerta de Moro and Puerta de los Pájaros. The Moro house, one of the oldest in Comillas, shows a large portrait of the Sacred Heart of Jesus on the facade of its square tower. The gate is amazing and unique and it was built with the Modernist style, which belonged to the Catalan Renaixença. Antoni did a great job.