The mission of Santa Ana de Velasco was the final World Heritage Site-inscribed mission to be established. 
It was founded by the Jesuit priest Fr. Julian Knogler in 1755. The original native inhabitants of the missions were the Covareca and Curuminaca tribes. The mission church was designed after the expulsion of the Jesuits between 1770 and 1780 by an unknown architect and built entirely by the indigenous population.
The complex, consisting of the church, bell tower, sacristy and a grassy plaza lined by houses, is considered to have the most fidelity to the original plan of the Jesuit reductions.
This was the most humble temple that I visited in my tour. But I think is has the most devoted people.
The town had just received electricity 3 years prior my visit. my plan was to stay 1 day in the town, but the bus that I needed to take passed 3 days later. 
When I got to the town I stayed at a guest house, it was the first time that I slept on a straw mattress. It was also the first time that I found I giant toad in the bedroom, it was a struble to take it out.
Since I had to stay I decided to go to a service at the temple, it was the first time in Latin America that I was asked to put on some pants. Even thou it was extremely hot and humid people are very conservative, and shorts are not acceptable.
Below is the the only existing original organ brought by the Jesuits to the missions. In santa Ana they still use it for special occasions. I was very lucky that I got someone to play the organ for me. People were very grateful that someone “as young”as me was interested in their history, from what I was told they hardly received any tourist.
My 3 days there pass very slowly, I walked around the small town like a maniac, to break the monotony of the week some people organize activities, which I attended, that night was a bingo game at the church.