Plaza de Castilla marks the northern end of central Madrid's Paseo de la Castellana, where broad traffic lanes meet the city's modern business skyline. The leaning Gate of Europe towers frame the boulevard, while Santiago Calatrava's obelisk gives the square its sharp vertical marker.
It is more a place to pass through than linger, but it is worth a look if you are interested in Madrid's late-20th-century architecture. Bus 27 follows the Castellana north from the museum district, making the ride itself a good way to see the city's formal spine change from grand avenues to high-rise Madrid.