World’s Largest Train Station Clock Erected in Switzerland

At the north entrance to the tunnel, a 23-foot high (7 meters) clock face, with a round red disc on the second hand with a circumference of over 2 1/2 feet (nearly 80 centimeters), tells travelers the time.

Rumored to allow even airplane passengers flying over the tunnel to set their watches to it, the clocks are 12 times larger than the 3,000-plus Mondaine clocks mounted on Swiss train stations, and are equipped with the famous second stop. At each full minute, the red second disk stands at the 12 for nearly two seconds, before making another of its slightly accelerated rounds.

This technique was introduced in the 1940s, when it helped people set their watches precisely.