[BrotherMan]

The single most interesting thing to do in San Antonio is the tour of the Alamo. But then, I'm not sure what would be interesting about it from a non-texan, non-american view point.

For Texans, it marks a turning point in their fight for independence from Mexico; a rallying point to oppose the oppressionary forces of the evil brown people. It's there if you want to peek in on a bit of Texas history. Other than that, there's the river walk, which I guess is now a commercialized tourist trap - but a very pretty one last time I was there.