One cruise line offered cruises from San Diego to Incan and Mayan historic sites in South America and Central America. Round-trip or one-way cruises to Chile, Argentina or Brazil.
Lima (Peru) shore excursions include the Incan wonder of Machu Picchu. The city itself has beautiful historic buildings and excellent restaurants.
Puerto Chiapas (Mexico) is the Pacific gateway to the Mayan world. The port is the starting point for excursions to the ruins at Izapa. Closer to town you can explore a rainforest or shop for local crafts.
From Puerto Quetzal (Guatemala) a flight to Tikal reveals a famous Mayan archaeological site.
The historic quarter of Valparaiso (Chile) is a World Heritage Site. Ride a funicular up to take in views over the city and ocean. About two hours inland is Santiago, the capital of Chile.