Franciscan Missions in the Sierra Gorda by Zoë Sheng
This will be a short review, more of an update maybe because there are already many reviews but nothing since 2014. The Sierra Gorda biosphere alone is worth visiting so the churches are maybe more of a bonus. The windy roads don't make for a fun ride if you have to deal with trucks slowing down the traffic to 20km/h and little chances to overtake most of the way. Mexican drivers can be very patient and stick behind the truck for a loooong time.
They look in good condition nowadays, almost as if they're new. I visited two of the churches on a Sunday, Jalpan was super busy and the church closed for celebrations. Landa was deserted and open. One can spend time inside but there honestly isn't much to see but for the ceiling decorations so I didn't miss much at the first church? The facades are what make the churches unique. So I stare at them for a while to see what's on display before moving on. Beautiful.