The Gateway Arch—which takes the shape of a catenary curve, or the curve formed by a chain held at two fixed points—was built using the “keystone-in-place” method of construction.

At 630 feet tall, the Gateway Arch is the tallest monument in the ... Helicopter crew finds missing toddler in high-tech rescue Keystone oil pipeline shut down after "mechanical bang" reported ...

Starting on May 1, the LED lights that illuminate the Arch at night will be turned off to help migrating birds find their way ...