Another short Metro ride this morning brought us out at Notre Dame. Being Sunday, Mass was being conducted but this didn't mean tourists were kept out. We were allowed to walk around the inside edge of this magnificent cathedral and enjoy the sounds of the service. The cathedral has been there since the 1100's and is truly wonderful. Outside the church is an underground crypt showing the remains of a Roman settlement which was originally on this site in the 2nd and 3rd century. After lunch we found Sainte-Chapelle another gem of High Gothic architecture. The building comprises two chapels, one above the other and was built in 1242 for King Louis IX. The upper chapel was used only by the King and his family, the lower chapel was the place of worship for the palace staff. It's a wonderful building famous for its vast walls of stained glass windows.