Every city has bridges leading into it, and for the most part they are completely un-newsworthy. Sure you have some that are tourist destinations due to their fame, like the Golden Gate Bridge in San Francisco or the Brooklyn Bridge in NYC, but none of them have what the Ann W. Richards Congress Avenue Bridge in Austin has - bats! Lots of them.
In 1980, the bridge underwent a series of renovations to strengthen it. The biggest change was underneath the bridge which carved out a series of narrow deep openings, creating an ideal resting place for bats. Shortly after renovation, a colony of Mexican free-tailed bats moved in. The colony population fluctuates year to year, but is estimated by the Bat Conservation International group to be between 750,000 and 1.5 million bats. This makes it the largest urban bat colony in the world.
The bats are migratory, spending their Summers in Austin and Winters in Mexico. While they are here, they do a great job of keeping the insect population down, consuming tens of thousands of pounds of them each year. In addition to being a benefit to the outdoor loving community, they are also a boon to local businesses as they attract as many as a hundred thousand tourists annually, generating millions in revenue for the city.
Each night during the warmer part of the year, which can start as early as March for Austin, the bats will begin to exit the bridge around dusk. It can take upwards of an hour for the bridge to be emptied, with a constant stream of bats flying out. There are numerous places to watch along the bank of Lady Bird Lake and on the bridge itself. For those looking for a more unique view, there are numerous bat watching cruises that can be taken ( http://lonestarriverboat.com )
The Ann W. Richards Congress Avenue Bridge is located at the Southern end of the city, and is within walking distance of both the Capitol and the South Congress shopping district.