Props to the Austin American-Statesman for allowing the use of their parking lot, and their grass to hang out on. Wear a hat.
Across Congress Street from the Statesman a sculpture, Nightwing, celebrates the bat.
Another convenient-for-tourists (but smaller) bat colony is reported 15 miles north of Austin, underneath the I-35 underpass at McNeil Road, Round Rock. Wear a hat.
Address: Congress Ave., Austin, TX
Directions: Congress Avenue Bridge on Town Lake, Austin American-Statesman parking lot on the southeast side, free parking to the public after 6 pm.
Hours: Bats take wing just before dark, usually -- March through November.