Lock Heart Gap is named after the British planter and engineer, Major Lockhart, who surveyed the area in the 19th century. The gap was originally used as a passage for transporting goods and people between Munnar and the nearby town of Mattupetty. Over time, the area has become a popular tourist destination due to its scenic beauty. The name 'Lock Heart' is believed to be a misspelling of 'Lockhart', but the name has stuck over the years.