the markets in the eastern part of the prefecture. Komatsuna and spinach are the most important vegetables; as of 2000, Tokyo supplied 32.5% of the komatsuna sold at its central produce market. With 36% of its area covered by forest, Tokyo has extensive growths of cryptomeria and Japanese cypress, especially in the mountainous western communities of Akiruno, Ōme, Okutama, Hachiōji, Hinode, and Hinohara. Decreases in the price of timber, increases in the cost of production, and advancing old age among the forestry population have resulted in a decline in Tokyo's output. In addition, pollen, especially from cryptomeria, is a major allergen for the nearby population centers. Tokyo Bay was once a major source of fish. Most of Tokyo's fish production comes from the outer islands, such as Izu Ōshima and Hachijō-Jima. Skipjack tuna, nori, and aji are among the ocean products. Tourism in Tokyo is also a contributor to the economy. In 2006, 4.81 million foreigners and 420 million Japanese visits to Tokyo were made; the economic value of these visits totaled 9.4 trillion yen according to the Tokyo Metropolitan Government. Many tourists visit the various downtowns, stores, and entertainment districts throughout the neighborhoods of the special wards of Tokyo. Cultural offerings include both omnipresent Japanese pop culture and associated districts such as Shibuya and Harajuku, subcultural attractions such as Studio Ghibli anime center, as well as museums like the Tokyo National Museum, which houses 37% of the country's artwork national treasures (87/233). The Toyosu Market in Tokyo is the largest wholesale fish and seafood market in the world since it opened on October 11, 2018. It is also one of the largest wholesale food markets of any kind. It is located in the Toyosu area of Kōtō ward. The Toyosu Market holds strong to the traditions of its predecessor, the Tsukiji Fish Market and Nihonbashi fish market, and serves some 50,000 buyers and sellers every day. Retailers, whole-sellers, auctioneers, and public citizens alike frequent the market, creating a unique microcosm of organized chaos that still continues to fuel the city and its food supply after over four centuries. Transportation Tokyo, which is the center of the Greater Tokyo Area, is Japan's largest domestic and international hub for rail and ground transportation. However, its airspace has been under the US military's exclusive control after World War II. Public transportation within Tokyo is dominated by an extensive network of "clean and