Palacio de las Cortes
From the Super Mario Wiki
The Palacio de las Cortes is the meeting grounds for Spain's Congress of Deputies and one of the Madrid landmarks in Mario is Missing that is attacked when the city is invaded by Koopa Troopas. In-game, the building is consistently called the Spanish Parliament, despite that not being the name of the building and not all of the Cortes Generales convening there. The Koopa Troopas steal the Lion's Tail from one of the lion statues at the front of the palace, leading to the entire building shutting down. Luigi eventually returns the Lion's Tail to the Palacio's information booth once he takes it back, and after proving that the tail is genuine by answering the questions below, the palace reopens.
Spain adopted its democratic constitution in 1978. This was two years after the death of General Franco, who had run the country for decades as a stuffy tyrant. Since then, Spain has been a democratic monarchy with the king as leader, although others have a say in the government. The Parliament, or governing body, meets in the Palacio de las Cortes. Two bronze lions guard the building. The bronze for the King of Beasts was melted down from a captured Moroccan cannon.