La Sainte-Chapelle (The Holy Chapel) on the Île de la Cité is both an official French national monument and a UNESCO world heritage site. Built in the 13th century, the intimate structure is considered one of the great achievements of Gothic architecture. It's also the site of popular chamber music concerts several evenings a week, featuring works like Vivaldi's The Four Seasons performed by a group known as Les Solistes Français (left). It's well worth a visit, both for the music and for the chapel's exceptional collection of stained-glass windows. Be sure to get concert tickets ahead of time online or at any of the fnac locations in Paris. Not too far away in the 5th arrondissement, the Church of St. Julien le Pauvre also offers highly regarded piano and vocal recitals on a regular basis. It's a lovely (and different) way to pass an evening in Paris.