What's going on

So the big archaeology meetings finished up. I had a good time, saw some good presentations, learned a few things, met a couple of new people and ran into a couple of folks I hadn't seen in years. I had a brief personal crisis that revolved around the tension between academic and contract archaeology, but now is not the time to talk about that, except to say that the nice thing about contract archaeology is that I got to go out in the field right after the meetings, unlike the academicians.
Most of this week I've been surveying outside of New Braunfels. I guess there's a housing development in the works for a big old piece of land, and this piece of land has a historical marker on it suggesting that it was the location of a Spanish mission. More intriguing is that the hill on the property is called "Mission Hill" and was apparently the location of an old German settlement as well. So the developer, realizing that bulldozing stuff like this might make people angry, has us surveying.
Try as we might, we couldn't find any traces of a mission. This could be because it was a small mission which existed for about 2 years. Or, it could be because the mission was probably somewhere else. Yep, there's competing historical markers in New Braunfels concerning the location of the mission.
We did maybe find some traces of the German settlement. There's 2 cisterns built into the sides of hills, both of rather unusual construction. One is partly brick-lined, with the lower portion is plaster covering the excavated bedrock where they dug out the hill. The bricks are pretty old, although we couldn't date them precisely. At the foot of the cistern, there's a retaining wall and most likely a small pool carved into the bedrock. Another strange thing is that there was not a single artifact nearby. Usually, there'd be at least a few bits of glass or metal or something but we couldn't find a thing. This cistern is not too far from two large houses at the top of the hill, but those likely date to the '20s and the cistern seems older.
The other cistern is basically in the middle of nowhere. It's made entirely of dressed limestone slabs, except for an opening at the bottom which has a brick arch. This thing is also probably 15 feet in total height/depth. It is also an unusual design, and also did not have a single artifact associated with it. It was also serving as a home for a baby vulture, which was not happy with us and kept hissing and growling at us. Tini saw a couple in a cave 2 weeks ago and said they were cute, but this one was about the size and look of a small, plucked chicken.
So, now that we checked out the property, we have to write it up and do some research to try and figure out just what the hell is going on there and whether it's something that might need some more work or preservation. At least we can tell the client that they don't need to worry about the mission.