Concierge.com's insider take:
Vegas-style shopping centers have become the most exciting attractions on land in the Zona Hotelera. Though exceedingly splashy and often stuffed with the same goods you can get back home, they're also a lively (and air-conditioned) break from hot days on the beaches. Local residents now treat malls like the main plazas of colonial cities, dressing in their finest to stroll about with their neighbors. Gondolas glide through canals at Plaza La Isla, a sprawling outdoor entertainment center with designer shops, movie theaters, hip restaurants, and the fanciest McDonald's this side of Buenos Aires. The kiddies get a kick out of the sharks at the aquarium there (Blvd. Kukulcán, Km 12.5). Marble and glass gleam at Luxury Avenue, where visitors shop for duty-free goodies from Montblanc, Cartier, and Swarovski and check out the latest Ferragamo and Zegna fashions (Blvd. Kukulcán, Km 13). The Avenue anchors the south end of Kukulcán Plaza (Blvd. Kukulcán, Km 13; www.kukulcanplaza.com), a recently remodeled air-conditioned behemoth with free Wi-Fi; a huge play area for children; multiple restaurants, from Ruth's Chris to Chocolate City; and a stunning stained-glass dome depicting the Mayan culture—there's even a sound and light show at 7:30 every evening.