The Western Ghats are a 1,500 kilometre-long ribbon of mountains that run through the southwestern part of India, forming a jagged edge that separates the high Deccan Plateau, which makes up most of the Indian peninsula, from the low-lying coast of the Arabian Sea.
As the land heats up during the summer, it pulls in a mighty body of cold air from the ocean. When this water-laden air hits the Western Ghats, it deposits torrents of water over the mountains, drenching the area for six months of every year.
UNESCO, which recognised the Western Ghats as a world heritage site in 2012, has listed them as "one of the best examples of the monsoon system on the planet".
The mountains moderate the tropical climate of the region, and an overwhelming 245 million people depend on these systems for their water. By extension, these mountains regulate the water cycle of India and its inhabitants, who make up one-sixth of the world's population.
Every year, the country waits with bated breath to see how the monsoon performs: Its behaviour is emotively referred to as "good" or "bad". The monsoons are so tied to the people that a bad monsoon can break a politician's career.
As a result of this incredible water system, the Western Ghats are lush. Their slopes are a global biodiversity "hotspot" - one of the top eight in the world. Their forests are some of the best examples of tropical evergreen forests anywhere away from the equator, and home to a staggering range of plants and animals. Many of these are endemic and found nowhere else on the planet. The mountains are also home to at least 325 globally threatened flora, fauna, bird, amphibian, reptile and fish species. There are four main types of forest here: wet evergreen, semi-evergreen, moist deciduous and dry deciduous.