Palakkad Gap

Palakkad Gap is a 30-40 kilometers (19–25 miles) wide low mountain pass in the Western Ghats, near Palakkad town in the South Indian State of Kerala. It has an elevation of 300 metres (980 ft). The hills rise to 1100m to the North of the gap, and 2000m to the South. The average height of the gap is 144m.

The gap is the lowest pass through the Western Ghats. It is also the only break in that stretch of the Ghats that otherwise runs along the entire eastern edge of Kerala, isolating the State from neighbouring Tamil Nadu. It acts as a corridor between the two States by linking Palakkad District of Kerala with Coimbatore District of Tamil Nadu, and has served as a vital part of the important trade route between the East and West coasts of peninsular India since ancient times. Palakkad Fort, stands as a reminder of the strategic importance the gap once had as a gateway to Kerala for would be invaders from the other side of the Ghats.

There are various theories about the origin of Palakkad gap. One among them is that it is caused by the landslide due to rivers flowing in opposite directions. The Bharatha Puzha river originates in the Palakkad Gap from rivulets and tributaries feeding from steep escarpment slopes along the flanks of the Ghats.

The gap is important to the climate of southern India in that it allows the moisture-laden Southwest monsoon winds into the Coimbatore region, which moderates Coimbatore's summer temperatures and generates greater rainfall in the region relative to the rest of lowland Tamil Nadu. At the same time, the district of Palakkad is during the summers warmer than the rest of Kerala because hot winds from Tamil Nadu blow in.

Historically, Palakkad gap has played a major role in enabling migrations into Kerala from other parts of India. Tamil Brahmins ("Palakkad Brahmins") are a prominent group that migrated to Palakkad from Thanjavur, Kumbakkonam and surrounding areas in Tamil Nadu via the Palakkad gap from the 15th century to 18th century. Also, right from 300 B.C. to 13th century, it also helped the Cheras rule entire Kerala and the areas of Kongunadu (Coimbatore, Erode, Karur) as one geographical unit.

Both the NH 47 highway and the Coimbatore-Shornur rail link joining Kerala to Tamil Nadu pass through this gap.