Air traffic controllers really need to be above it all, in order to perform at their best. For this, they need a choice perch to oversee the entire airport platform and manage its traffic - the Control Tower. All are at least several dozen metres above the ground, but some edifices are more imposing than others. And to answer your question, the largest one is in Malaysia.
Looking out from the 33rd floor, at a height of 439 ft (133.8 m), Kuala Lumpur International Airport's West Tower has proudly held the record of the world's tallest control tower since April 30th, 2013. It dethroned Bangkok's Suvarnabhumi airport in Thailand 434 ft (132.2 m high).
Launched in May 2012, construction of the West Tower took ten months and cost €16 million euros to build. Kuala Lumpur International Airport, which covers a total area of 24,200 acres (9,800 hectares), has three runways over 2.5 miles (4 km) long and 114 boarding gates. Last year nearly 53 million passengers passed through its doors.