Benjasiri is the name given by His Majesty the King. The park was built by Treasury Department under the order of Ministry of Finance on December 19, 1989. The place was formely a head office of Meteorology Department, which was handling with unreliable results of air condition tests amid Bangkok pollution and had to move to Bangna-Trad road. As Her Majesty the Queen of King Rama IX has continuosly dedicated herself for the quality of lives and health of her people in many different ways, environment preservation was one of the duties she has mostly emphasized on. For that reason, Benjasiri Garden was gratefully originated for Her Majesty the Queen in the occasion of her 5th cycle birth anniversary on August 12, 1992.