Peru is a representative democratic republic divided into 25 regions, with its capital in Lima –the largest and most populated city of the country, with over 10 million inhabitants.
Peruvian territory was home to ancient cultures spanning from the Norte Chico civilization in Caral (one of the oldest in the world, with settlements as old as 3200 BC) to the Inca Empire, the largest state in Pre-Columbian America. The Spanish Empire conquered the region in the 16th century and established a Viceroyalty with its capital in Lima, which included most of its South American colonies. Ideas of political autonomy later spread throughout Spanish America and Peru gained its independence, which was formally proclaimed in 1821 after the occupation by military campaigns of José de San Martín and Simón Bolívar.
The combination of tropical latitude, mountain ranges, topography variations, and two ocean currents gives Peru a large diversity of climates. The coastal region has moderate temperatures, low precipitations, and high humidity. In the mountain region, rain is frequent in summer, and temperature and humidity diminish with altitude up to the frozen peaks of the Andes. The Peruvian Amazon is characterized by heavy rainfall and high temperatures, except for its southernmost part, which has cold winters and seasonal rainfall.
Peru is an extremely biodiverse country with habitats ranging from the arid plains of the Pacific coastal region in the west, to the peaks of the Andes mountains vertically extending from the north to the southeast of the country, to the tropical Amazon Basin rainforest in the east with the Amazon river.
The Andes mountains run parallel to the Pacific Ocean; they define the three regions traditionally used to describe the country geographically. The costa (coast), to the west, is a narrow plain, largely arid except for valleys created by seasonal rivers. The sierra (highlands) is the region of the Andes; it includes the Altiplano plateau as well as the highest peak of the country, the 6,768 m (22,205 ft) Huascarán. The third region is the selva (jungle), a wide expanse of flat terrain covered by the Amazon rainforest that extends east.
Because of its varied geography and climate, Peru has a high biodiversity with over 20,000 species of plants and animals. Peru has over 1,800 species of birds (120 endemic), and 500 species of mammals and over 300 species of reptiles. The hundreds of mammals include rare species like the puma, jaguar and spectacled bear.