Plaza de Cibeles is my favorite plaza in Madrid - between the beautiful buildings (the Palacio de las Comunicaciones), La Castellana (the famous tree-lined paseo) and the view of the Puerta de Alcala, it's the intersection of some of the best sights in Madrid. If you happen to be in town for a Real Madrid win, head here as it also happens to be where Madrileños go to celebrate those big wins!