I love the Lady Bird Johnson Wildflower Center; I think it's a really special place. The grounds themselves are lovely--there are calm pools of water, bubbling brooks, and beautiful architecture and sculptures. There are loads of native plants and wildflowers in the gardens. I also recommend going for a walk in one of the trails that are on either side of the main campus of the Wildflower Center--you will feel like you are really out in the Hill Country. The admission is a little pricey at $8 per adult, but I think the overall ambiance makes it worth it. They also have a cute gift shop and lovely little cafe.