Interesting places near Houston for day or weekend trips

Hi guys,

I've lived in Houston a while now and I work a lot as most of you do too. I use my vacations to go somewhere far once a year, since I don't get that much vacation time (15 days a year in sick time. Woohoo!).

This year me and my wife have decided to get out of the city more and explore what Texas has to offer either in a day trips or weekend trips, leaving Friday afternoon coming back on Sunday.

Thing is we are both immigrants and not really sure where to start or what are the best places to visit.

We really are into most things, history, nature, anything that's not a big sprawling concrete City (which isn't a bad thing it's just we want to get out of this place once in a while).

Any advice would be awesome.