From the altiplano to the Amazon basin, Bolivia borders five countries and comprises nearly every microclimate and ecosystem imaginable. It's most famous for the Andes, which take up a large chunk of the west. Also well known are the vast jungle regions of Amazonia, which extend all the way east into Brazil. But Bolivia has a surprisingly varied series of ecosystems within those two major regions. Mountain areas vary from cool and dry (as in the high-altitude cities of La Paz and Potosí), to temperate (the cities of Cochabamba and Sucre), to warm and pleasant almost year-round (in the fertile, grape-growing lands near the southern city of Tarija). Jungle areas also vary: from very humid and warm, as in Santa Cruz, to the more temperate climates in the northwest province of Pando. In the northeast province of Beni, encompassing the city of Trinidad, the hot, wet climate is occasionally broken by cold spells called surazos.