right|frame|Map of Asia showing the location of Sri Lanka
Sri Lanka, formerly called Ceylon, is an island country in the Indian Ocean, southeast of the Indian subcontinent, in a strategic location near major sea lanes. The nation has a total area of , with of land and of water. Dozens of offshore islands account for the remaining 1552 km<sup>2</sup> area. The largest offshore island, Jaffna Island is separated by Chundikulam lagoon and Mannar Island, is linked to Adam's Bridge, a land connection to the Indian mainland, which is now mostly submerged with only a chain of limestone shoals remaining above sea level. According to temple records, this natural causeway was formerly whole, but was breached by a violent storm (probably a cyclone) in 1480. The formation is also known as Rama's Bridge, as according to Hindu mythology, it was constructed during the rule of Lord Rama.
Sri Lanka's climate includes tropical monsoons; the northeast monsoon (December to March), and the southwest monsoon (June to October). The granulite facies rocks of the Highland Series (gneisses, sillimanite-graphite gneisses, quartzite, marbles, and some charnockites) make up most of the island and the amphibolite facies gneisses, granites, and granitic gneisses of the Vijayan Series occur in the eastern and southeastern lowlands. Jurassic sediments are present today in very small areas near the western coast and Miocene limestones underlie the northwestern part of the country and extend south in a relatively narrow belt along the west coast. The metamorphic rock surface was created by the transformation of ancient sediments under intense heat and pressure during mountain-building processes.
Humidity is typically higher in the southwest and mountainous areas and depends on the seasonal patterns of rainfall. World Meteorological Organization (precipitation only)
|source 2 = Deutscher Wetterdienst (extremes)
|date=May 2012
Ecological zones
thumb|right|350px|Precipitation and irrigation map of Sri Lanka
The pattern of life in Sri Lanka depends directly on the availability of rainwater.]]
The dominant pattern of human settlement during the last 2,500 years has consisted of village farming communities.