Hoover Dam 胡佛大坝

Located in the Black Canyon on the Arizona-Nevada border, this concrete arch-gravity dam—which stands at a jaw-dropping 726 feet tall—attracts approximately 1 million visitors each year. Funded by Congress during the Depression, the dam controls floods, provides irrigation water and produces hydroelectric power. Photo courtesy of Wikipedia.

这座位于亚利桑那州（Arizona）-内华达州（Nevada）边界黑峡谷的混凝土拱形重力大坝，以令人瞠目结舌的726英尺高度站立着，每年吸引了大约一百万的游客。这座由国会在经济大萧条时期修建的大坝，控制着洪流、提供着灌溉用水并且生产着水力发电的能量。照片由维基百科（Wikipedia）提供。