8 Paris 9ème arrondissement: église de la Trinité.
When I came to visit this church it was in the middle of a major renovation of the outside, which is a chance to explain a few things about churches in France for people who come from elsewhere. At the beginning of the 20th century there were laws and negotiations sorted to deal with relations between the State and the ( pretty powerful) Catholic Church. One of the decisions is that all churches built before 1905 would become the property of the local government, who would lease them free of charge to the parishes (the cathedrals became the property of the national government). One of the advantages for the Church is that, as I understand it, repair and renovation is a government responsibility. We can see this in some of the signs on the outside of the church, shown below. There is a non-religious tone to some of them ("a new church for a new neighbourhood!"). Such historic monuments are now allowed to sell advertising space on the scaffolding, as long as the money goes to help fund the repairs and renovations.
Anyway, the church is open while the renovation takes place. Very nice ceramic Staions of the Cross, a beautiful baptismal font, and some interesting paintings of Eden etc. were my favourite parts.
The ten bluish marble pillars around the altar represent the ten commandments, apparently.