Tokyo officially Tokyo Metropolis is one of the 47 prefectures of Japan and located on the eastern side of the main island Honshu. The twenty-three special wards of Tokyo, each governed as a city, cover the area that was once the city of Tokyo in the eastern part of the prefecture, and total over 8 million people. The population of the prefecture exceeds 12 million. The prefecture is the center of the Greater Tokyo Area, the world's most populous metropolitan area with 35 million people and the world's largest metropolitan economy with a GDP of US$1.191 trillion at purchasing power parity in 2005. Tokyo is the seat of the Japanese government and the Imperial Palace, and the home of the Japanese Imperial Family. Tokyo was originally known as Edo, meaning estuary. Its name was changed to Tokyo when it became the imperial capital in 1868. During the early Meiji period, the city was also called "T??????kei", an alternative pronunciation for the same Chinese characters representing 'Tokyo'. Some surviving official English documents use the spelling "Tokei". This pronunciation is now obsolete. Tokyo was originally a small fishing village named Edo. In 1457, ta Dukan built Edo Castle. In 1590, Tokugawa Ieyasu made Edo his base and when he became shogun in 1603, the town became the center of his nationwide military government. During the subsequent Edo period, Edo grew into one of the largest cities in the world with a population topping one million by the 18th century. It became the de facto capital of Japan even while the emperor lived in Kyoto, the imperial capital. After about 263 years, the shogunate was overthrown under the banner of restoring imperial rule. In 1869, the 17-year-old Emperor Meiji moved to Edo. Tokyo was already the nation's political and cultural center, and the emperor's residence made it a de facto imperial capital as well with the former Edo Castle becoming the Imperial Palace. The city of Tokyo was established, and continued to be the capital until it was abolished as a municipality in 1943 and merged with the "Metropolitan Prefecture" of Tokyo. Central Tokyo, like Osaka, has been designed since about the turn of the century (1900) to be centered around major train stations in a high-density fashion[citation needed], so suburban railways were built relatively cheaply at street level and with their own right-of-way. This differs from cities in the United States, such as Los Angeles, that are low-density and automobile-centric. Though expressways have been built in Tokyo, the basic design has not changed. Tokyo Metropolitan Government BuildingTokyo went on to suffer two major catastrophes in the 20th century, but it recovered from both. One was the 1923 Great Kant?????? earthquake, and the other was World War II. The bombing of Tokyo in 1945, with 75,000 to 200,000 killed and half of the city destroyed, were almost as devastating as the atomic bombs of Hiroshima and Nagasaki combined. After the war, Tokyo was completely rebuilt, and showcased to the world during the 1964 Summer Olympics. The 1970s brought new high-rise developments such as Sunshine 60, a new and controversial airport at Narita in 1978 (some distance outside city limits), and a population increase to about 11 million (in the metropolitan area). Tokyo's subway and commuter rail network became one of the busiest in the world, as more and more people moved to the area. In the 1980s, real estate prices skyrocketed during a real estate and debt bubble. The bubble burst in the early 1990s and many companies, banks, and individuals were caught with mortgage backed debts while real estate was shrinking in value. A major recession followed, making the 1990s Japan's "lost decade" from which it is slowly recovering. Tokyo still sees new urban developments on large lots of less profitable land. Recent projects include Ebisu Garden Place, Tennozu Isle, Shiodome, Roppongi Hills, Shinagawa (now also a Shinkansen station), and the Marunouchi side of Tokyo Station.