Strasbourg Cathedral, officially known as the Cathedral of Our Lady of Strasbourg, is a Roman Catholic cathedral located in Strasbourg, Alsace, France. Renowned for its stunning Gothic architecture, it was once the world's tallest building, a title it held from 1647 to 1874. The cathedral's construction started in the 12th century and was completed in 1439, making it one of the finest examples of high gothic architecture. Its impressive facade is characterized by a profusion of sculptures and a distinctive single spire, which reaches a height of 142 meters (466 feet). Inside the cathedral, visitors can marvel at the elaborate astronomical clock, which is considered a Renaissance-era masterpiece, and the exquisite stained glass windows, some of which date back to the 12th century. The cathedral also offers panoramic views of Strasbourg and the surrounding region from its viewing platform.