Nuit des Cathédrales is an annual event where cathedrals across France (and some parts of Europe) open their doors for an evening of special tours, concerts, light shows, and cultural activities. Visitors can experience these historic spaces in a unique atmosphere, often illuminated with stunning lighting displays and filled with music, art exhibitions, and guided tours. The event is typically free to the public and provides a rare chance to explore cathedrals after dark, highlighting their architectural beauty and spiritual significance.