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 western 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 the 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. North side of the gap is hills with a height of 1100m and south side the same with 2000m height. The average height of the gap is 144m. 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 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. Also, in the summers, the district of Palakkad is warmer than the rest of the state because hot winds from Tamil Nadu blow in.