Located at the intersection of Amarit Road and Phakdi Dumrong Road, this is Thailand's first mountain tunnel, constructed with reinforced concrete. It measures 273 meters in length, 9 meters in width, and 7 meters in height, featuring two traffic lanes. The tunnel was opened to the public on January 1, 2001, and is illuminated at night to facilitate safe passage. Inside the tunnel, pedestrian walkways run along both sides of the traffic lanes, allowing visitors to easily cross to the other side and admire the decorative lights.