The first known drug-smuggling tunnel in Nogales, Ariz., was found in August 1995 beneath an abandoned church 150 yards from the border. Since then, more than 90 illicit underground passageways have been discovered in various states of completion. Here, a look at several of the discoveries.

Photographs by AP Photo(1), Reuters(2); Graphic by Bloomberg Businessweek; Satellite Image: USGS