The House of the Temple is located at 1733 Sixteenth Street NW, Washington, DC. Designed by architect John Russell Pope, this monumental building serves as the national headquarters of The Supreme Council of Freemasonry. The Grand Lodge of the District of Columbia laid the cornerstone in 1911, and the building was completed in 1915. Its architecture is an adaptation of the famous Mausoleum at Halicarnassus, one of the "Seven Wonders of the Ancient World." There have been few architectural alterations since the construction of the building. The House of the Temple has been open to the public for guided tours since it opened in 1915.