Here are some things I did when I was there a couple of years ago: Alamo, riverwalk, took a horse and carriage ride around the city (we were bored and it was a good deal), spent hours in the souvenir shops reading the awesome slogans on the t-shirts (if you're into politics). We also found this really cool historic town called Gruene, it's about a 40 minute drive from San Antonio but worth it! There are a bunch of shops along a road and a town hall which often has performers. We spent quite a bit of time browsing the shops, playing pool in the town hall, sitting by the fire pit, and enjoying the vibe.