Saint Isaac's Cathedral, also known as Isaakievskiy Sobor in Russian, is a magnificent edifice situated in Saint Petersburg, Russia. It was commissioned by Tsar Alexander I in the early 19th century and took more than 40 years to construct, from 1818 to 1858, under the direction of the French-born architect Auguste Montferrand. As one of the most impressive landmarks of the Russian Imperial capital, Saint Isaac's Cathedral is the largest Russian Orthodox cathedral in the city and was the tallest Eastern Orthodox church upon completion. This architectural marvel is adorned with a variety of materials, including malachite and lapis lazuli, and is notable for its massive central gold-plated dome, which dominates the skyline of Saint Petersburg. The interior is equally opulent, decorated with detailed mosaics, paintings, and columns made of granite and marble. The cathedral's colonnade provides breathtaking panoramic views of the city. Despite its religious origins, Saint Isaac's served as a museum during Soviet times and today functions as both a museum and a place of worship.