The best view in Mazatlán gets you some exercise, too—a 30- to 45-minute climb along natural trails and rough-hewn stairs to the lighthouse that since 1571 has been warning ships from atop Cerro del Creston, 515 feet above the sea. Wear sturdy shoes, bring a bottle of water, and, if you go up to watch the sunset, maybe a flashlight for the trip back down. Note that it takes about 20 minutes to walk from the southern terminus of Paseo Claussen (the end of the malecón) to the start of the lighthouse trail, but it's a lovely route, most of which skirts the water. When Claussen ends just follow the signs for Paseo del Centenario for a few blocks through residential streets until you reemerge on the seaside road.
Southern terminus of Paseo del Centenario, Mazatlán, 82000, Mexico