Sample Clues
Founded in 1802, this military group surveys roads & canals, builds lighthouses & maps navigation channels
the Army Corps of Engineers
The Itaipu, one of these 5 miles wide on the Brazil-Paraguay border, inspired a Philip Glass symphony
a dam
The U.S. will stop operating this 50-mile-long passageway in the year 2000
the Panama Canal
On opening day in 1937, the San Francisco Chronicle referred to it as a "35 million dollar steel harp"
the Golden Gate Bridge
This horseshoe-shaped, glass-bottomed structure extends 4,000 feet over the Colorado River in the Grand Canyon
the Skywalk