Washington, D.C. is low and sprawling. The federal Height of Buildings Act of 1910 prohibits buildings exceeding the width of the adjacent street plus . Despite popular belief, no law has ever limited buildings to the height of the United States Capitol or the Washington Monument, which remains the district's tallest structure. City leaders have criticized the height restriction as a primary reason why the district has limited affordable housing and traffic problems caused partly by suburban sprawl. The district is divided into four quadrants of unequal area: Northwest (NW), Northeast (NE), Southeast (SE), and Southwest (SW). The axes bounding the quadrants radiate from the U.S. Capitol. All road names include the quadrant abbreviation to indicate their location and house numbers generally correspond with the number of blocks away from the Capitol. Most streets are set out in a grid pattern with east–west streets named with letters (e.g., C Street SW), north–south streets with numbers (e.g., 4th Street NW), and diagonal avenues, many of which are named after states. The City of Washington was bordered by Boundary Street to the north (renamed Florida Avenue in 1890), Rock Creek to the west, and the Anacostia River to the east. Washington's street grid was extended, where possible, throughout the district starting in 1888. Georgetown's streets were renamed in 1895. Some streets are particularly noteworthy, including Pennsylvania Avenue, which connects the White House to the Capitol, and K Street, which houses the offices of many lobbying groups. Constitution Avenue and Independence Avenue, located on the north and south sides of the National Mall, respectively, are home to many of Washington's iconic museums, including the Smithsonian Institution buildings and the National Archives Building. Washington hosts 177 foreign embassies, constituting approximately 297 buildings beyond the more than 1,600 residential properties owned by foreign countries, many of which are on a section of Massachusetts Avenue informally known as Embassy Row. Architecture The architecture of Washington, D.C. varies greatly and is generally popular among tourists and locals. Six of the top 10 buildings in the American Institute of Architects' 2007 ranking of "America's Favorite Architecture" are in the city: the White House, Washington National Cathedral, the Jefferson Memorial, the United States Capitol, the Lincoln Memorial, and the Vietnam Veterans Memorial. The neoclassical, Georgian, Gothic, and Modern styles are reflected among these six structures and many other prominent edifices in the city. Many of the government buildings, monuments,