I particularly enjoy visiting the missions. Here is a link to an explanation of the 5 missions in SA.
My favorites were the Alamo and Mission San Jose, if you wanted to visit one other than the Alamo

As someone said, the missions offer history, archeology, art, archjitecture, culture, tradition....

I don't know what day you will be there, but we also attended a few services while we were ther, the mariachi Mass at Mission San Jose at noon on Sundays was so lively and full of culture - the music, singing, dancing, the 'relaxed' nature of the service with them announcing and celebrating parishioners anniversaries/weddings etc with them getting in the aisle and dancing ....it was enough to make me want to convert !

Or maybe you will be there on one of the feast days, which also brings special celebrations.

Read some info on them to see if one appeals to you to visit. Just walking through them and around the grounds is amazing.

We also enjoyed the Riverwalk and El Mercado area.

We arrived on a Friday around noon and left Sunday evening.

oops, forgot the link:
http://tinyurl.com/ya5ywv

I am so happy I fouind this thread. It looks like there are a lot of good tips here. We will be in San Antonio for about 4-5 days and planned on going to Fiesta and the Riverwalk, beyond that - we weren't sure. My boys ar 8 and 9.

Texastraveler,
Your sons might like the zoo and Brackenridge Park. They have a neat chair lift that you can ride (or at least they did years ago when I last visited.)

For the original post, I went to the King William district for the first time a few years ago and I enjoyed it. I especially liked eating breakfast at the Guenther House. I think that a walk in this district is a nice diversion from the typical sites on the Riverwalk.

If the chair lift ilovetulips mentions is the one I'm thinking of it was taken down years ago for, I believe, maintenace and liability issues, fyi.

We like the zoo--recently, the butterfly structure re-opened after being demolished by a fallen oak tree.

http://www.sazoo-aq.org/support/butterflies.html

The bird house at the zoo is a hoot. The parrots etc will come sit on your shoulders or arms as you walk through...and do other things to your shoulders and arms, and maybe hair too while they are at it. In this one instance, baseball caps are a good thing. Remember, "in one end and out the other". :D

AnnMarie, I haven't been to the Zoo and park area since college. I am sorry to hear that they let the chair lift go, it was great to get a bird's eye view of the area.

You're in good company as a lot of people were disappointed to see it go. In retrospect, it was a pretty unique feature for a park in San Antonio!

OO, lol. :-)