Iquique's main beaches are south of downtown, of which Playa Cavancha, at the corner of Avs Arturo Prat and Amunátegui, is the most popular. It's pleasant for swimming and body-boarding but sometimes gets crowded. There are also some decent surf breaks along its rocky northern parts, and a playground for children. In summer, the kiosk run by the municipal tourist office dishes out useful info.
Further south, crashing waves and rip currents at scenic Playa Brava make it dangerous for swimming, but there's plenty of space to sunbathe. Toward the hills, look for the massive dunes of Cerro Dragón, which looks like a set for a science-fiction movie.
Taxis colectivos run to Playa Brava from downtown – look for the destination on the sign atop the cab. There are scores of sandy beaches further south, but you'll need to rent a car or bike, or take a taxi.