One hundred and ninety-three unique stone tablets are set into interior walls of the Washington Monument, donated to the monument in honor of the nation's first president, George Washington. Most of the stones date from 1849 to 1855. Sixteen stones date to the twentieth century. The last stone was installed in 2000. There is a stone from every state, and also from fraternal and community organizations, cities and towns, foreign countries, and individuals. Stone types include granite, marble, limestone, sandstone, soapstone, and jade. Some stones are simply cut with incised text while others are carved in relief with ornament and figures or, in some cases, are fitted with bronze and silver plaques and letters. The stones range in size from 2-by-2 feet to 6-by-8 feet and are placed at heights from 3 feet to 16 feet above each landing of the stair case; one is placed above the stairs. Landings-or levels-are marked by their height (e.g., 30-ft. level, 180-ft. level)