I saw a similar church in the Czech Republic, in the town of Kutna Hora. San Bernardino is no less interesting. And it's very good that you can take pictures in it. Looking at the skulls makes you think about the frailty of life. The entrance to the chapel with the skulls is located to the right in an inconspicuous corridor.Admission is free.But besides this room, there is also a large hall, beautiful enough to look at it.