The Sea of Cortés is home for countless species of marine plants and animals, forming such a unique ecosystem that it was baptized by Jacques Cousteau as "The Aquarium of the World." Dotted with underwater mountains and canyons, the Sea of Cortés circulates huge amounts of nutrient-enriched water, producing seasonally heavy plankton blooms which in turn contribute to the massive diversity of tropical and pelagic fish found throughout its waters.

In addition to the Gray Whale calving migration to the three major warm-water lagoons, the Sea of Cortés hosts resident pods of various species of sea mammals including Sperm whales, Orcas, Humpback whales, Blue whales and Fin whales, often visible while sailing in these rich waters. Sea lion colonies and transient gigantic pods of dolphins lure thousands of watersports enthusiasts who congregate in La Paz, attracted by the opportunity of interacting with these friendly creatures. Giant mantas, massive whale sharks and impressive numbers of sharks, especially hammerheads, have made La Paz shine among the best worldwide scuba diving destinations. There are more than 25 first-class dive spots around the many islands surrounding the bay of La Paz, Espíritu Santo, San José and Cerralvo.

The surrounding desert is an intriguing, unique and extremely beautiful ecosystem full of endless surprises. Over centuries, its flora and fauna evolved endemic characteristics due to their relative isolation. Strange looking valleys of sentinel-like cardon, primitive cirios, elephant trees and thorny chollas make for some of the 4,000 different plants that form the spiny green carpet on the sandy earth. Many resident birds and migratory species are found here as they winter and pass by on their migration to southern locations. Hawks, wrens, woodpeckers, the great roadrunner, the Xantus Hummingbird and the Gray Thrasher are common sights. Desert Bighorn, foxes, coyotes, pumas, desert mice and squirrels are abundant.

Thousands of years ago, a primitive tribe of hunters and gatherers created countless rupestrian paintings in caves and gorges depicting life size human figures, hunting scenes, families, animals and even what appear to be extraterrestrials. The largest concentration of this spectacular prehistoric art is found in the Sierra de San Francisco and Guadalupe, however, hiking through the numerous ravines and streambeds of the south allows visitors to discover many of these astonishing sites near La Paz.

Just south of the city, at the edge of the Tropic of Cancer, stands the Sierra de la Laguna. This mountainous mass, declared a biosphere reserve in June of 1994, rises to an altitude of almost 2,200 meters, encompassing an extraordinary Darwinian paradise of birds and endemic plants. Its climate and vegetation change dramatically relative to the elevation. From sea level to 400 meters, the xerophilous brushwood prevails; from 400 to 1,200 meters, the driest of the semi-arid climates predominates, with the characteristic semi-deciduous forest, scattered with plants not found in other parts of the peninsula. From 1,200 meters to the highest peaks, the temperate climate and the abundance of rainfall favor the undisputed kingdom of pines and piñon-oaks. As you ascend the sierras, the landscape transforms radically, with sudden streams flowing into crystalline pools.