This was the last of the four missions I went to go see. After seeing all 4 of them, I'd say this was my second favorite. It's a gorgeous building, outside very rugged and old, inside (the church) looks like a brand new building painted very vibrantly; I believe it is still used for church services on Sunday. You can freely walk around the grounds and the rangers that work there are very giving with their mission knowledge. It's free, ample parking. I suggest going during the week when it might not be as busy and you don't have to deal with crowds while taking photos.
The grounds are the most basic of the missions I noticed. Which makes it maybe not as appealing on the grounds. No walls surrounding it and no real defense as it appeared to me which limits the history a little.
They discovered some really cool frescos on the walls, which are pretty cool to check out. But with all the cleaning efforts, some of the rooms, right now, are closed off. Not a big deal, you can still look inside, but it definitely limits the experience.
Check it out! It is worth the trip. Won't take long so don't plan a whole day around it. I saw the entire thing in 20- 30 minutes. Make sure to go to all the missions, they aren't far from each other and it makes for a pretty cool couple of hours checking them out. Just make sure to talk to the rangers for cool facts you might not find out otherwise.
Also, please be respectful. I noticed some people leaving trash there and eating in the church. I know the tripadvisor community is a good honest group, but it disappoints me when I see people so blatantly disrespecting these priceless historical artifacts. *I'll get off my soap, enjoy!
This review is the subjective opinion of a TripAdvisor member and not of TripAdvisor LLC.