[1] It has gained importance with trans border movement enabled between Myanmar and India following the 165 kilometres (103 mi) Tamu–Kalay section of India–Myanmar–Thailand Trilateral Highway built by the Border Roads Organization of India under the Look-East Connectivity policy.

[1] A votive tablet unearthed in Kalay in 1983, with a Mon language by ညောင်ဦး စောရဟန်း the first ruler was his son, the inscription, refers to the "Aniruddha, the Great King".

[4][5] During the Second World War, Kalay was an important regrouping point for the British during their retreat from Burma in 1942 because of the relatively easier access to India along the Manipur River (the alternative was to march through malarial forests from Kalewa to Tamu).

[6] On September 19, 2007, 200 monks marched through the streets of Kalay as a part of the 2007 Burmese anti-government protests.

On September 24, students marched from Kalay University with posters and protested, demanding the release of Aung San Suu Kyi and two other political prisoners.

[7] In July 2015, a monsoon rain triggered a natural disaster, and a state of emergency was declared in four regions of the country.

[1] The population of Kalay is estimated to be 400,000, comprising 55% Bamar, 35% Chin and 10% other nationalities and foreigners.

[1] The valley town, with its tranquil atmosphere, is inhabited in equal numbers by the Chin community and Bamars.

Cars, jeeps, trucks, fire engines, trailers, three-wheeled motorcycles are manufactured in the Kalay Industrial Estate.

The town's electricity needs are met from the MāNePu Hydroelectric Project, which also helps promote industries.