The Mecklenburg Aquatic Center is the downtown pool for the county. There are some high schools with olympic sized swimming pools already in them in Charlotte, but this serves the high schools with no pool as well as holds tournaments for big events.
It is a great pool, cool enough that the men's olympic decided to do their training there as they ran up to the Beijing Olympics. The word on the street is that Michael Phelps and the rest of the relay team trained at this complex in uptown Charlotte.
The pool is massive and is home to many of the big swim meets. I think they are a lot like high school track meets. There are a ton of people at them and they don't happen very often. The other thing is that seems like the only people who know about track meets or swim meets are the people who do the swimming themselves.
There is another big stadium pool in Charlotte at Providence High School in South Charlotte. I've never been to that one and really don't know much about it. But I think it is the only other pool that they use for swimming events in the city of Charlotte.