The church of St. Nicholas is located in the heart of Nantes. It´s impressive organ is the main attraction. It was destroyed during World War II and rebuilt in 2002. I recommend you visit this church on the day of "La fête de la musique" (June 21), when several musicians give life to this old masterpiece. It is one of the few occasions when the organ is played so it´s definitely worth it. The church is very beautiful and the acoustics are great.