Argentina's top seaside resort boasts more than 10 miles of sandy Atlantic beaches, which are packed during the Southern Hemisphere summer in January and February. Once an elite enclave, it now attracts visitors of all budgets, who venture away from the sand to take in the neo-Gothic Cathedral San Pedro, eat fresh fish at the port and shop for handmade wool garments. The family-friendly Museo del Mar has a tide pool and a collection of more than 30,000 seashells.