Build It High, Long, Strong

A wooden plank across a small stream makes a fun bridge.

- Rebecca Thornburgh

But a long bridge for lots of people and cars needs to be built especially strong so it will never sag or break.

The Golden Gate Bridge in San Francisco is nearly two miles long and hundreds of feet high. It’s built to be long and strong. Under the water, its two tall towers stand firmly on the hard rock at the bottom of the bay.

Long, thick steel cables hang over the two towers. They stretch from one end of the bridge to the other. On land on each side of the bay, the cables are anchored into tons of heavy concrete so they do not slip.