What’s more, the new park is revitalizing city attractions that have languished off the tourist radar but now suddenly seem at the center of the action. The fledgling multidiscipline arts center known as Matadero Madrid in the old slaughterhouses anchors the park to the south and has been swarming with people since Madrid Rio’s opening weekend. Now that the highway and its tangle of access ramps no longer run between them, several once-isolated parks like the Casa de Campo, Campo de Moro and Parque del Oeste now practically meet at the river’s edge.

Reuniting the city center with its southwestern neighborhoods (area real estate prices have skyrocketed accordingly), the park’s 33 bridges range from Renaissance-era to right now. The time warp is nowhere more visible than at the early-18th-century Puente de Toledo. Its harmonious rhythm of arches and curved bulwarks is echoed just a bit farther downstream in the corkscrew-shaped cylinder of steel designed by Dominique Perrault for the Puente de Arganzuela, the new bridge that is rapidly becoming Madrid Rio’s most popular photo backdrop.

Nearby, the new Parque de la Arganzuela is already a neighborhood favorite. It features a quirky playground with giant sliding boards — some wide enough for parents and kids to slide side-by-side — and other novel amusements, like a tirolina (similar to a zipline, it transports riders, one at a time, about 100 feet across the park). As the summer starts to heat up, visitors can cool down on the new urban “beaches,” large elliptical fountains designed for frolicking in jets of water and clouds of refreshing mist. At night, the Puente de Arganzuela lights up like a piece of an alien rocket fallen to earth.

Taking in the scene, Ana Martinez, a local architect who has worked with both private and municipal clients, said that unlike the new sports arena La Caja Mágica and other recent public projects that require admission tickets, “the river park is something that anyone in the city can enjoy every single day of the year.”

Maps of the new park are available from the city’s tourist information kiosks (there is one near the Puente del Rey) and also online at esmadrid.com/madridrio.