Iwaki is a city located in the southern part of the Hamadōri coastal region of Fukushima Prefecture, Japan.A designated core city, Iwaki is also one of the growing number of hiragana cities. Its total area is 1,231.35 km², making it the 10th largest city in Japan (2010). Its estimated population as of May 2011 is 337,288, making it the biggest city of the prefecture. Iwaki has a population density of 270 persons per km².The present "Iwaki City" started as the merger of 14 municipalities on October 1, 1966. The city was the third hiragana city, following Chino, Nagano and Mutsu, Aomori. The area was the largest in Japan at the time. The city works as an industrial hub of Tōhoku region, and is rich in sightseeing resources. As of 2005, about 7.6 million sightseers visit the city a year. Every year Iwaki hosts the Taira Tanabata Festival from 6–8 August.HistoryThe forms いわき, 石城, 岩城, 巖城, 巌城, and 磐城 are all ways of writing "Iwaki," which means "rocky castle". Today, いわき is the most common written form.Under the Taika Reform of 645 AD, the central government formed "Iwaki district (磐城郡)" in the northern part of the present city and "Kikuta district (菊多郡)" in the southern part. In 653, the Iwaki district incorporated part of Taga Province and became Iwaki district(岩城評). In 718, Iwaki Province was formed, which was composed of five districts with Mutsu Province: Iwaki (岩城), Shineha, Namekata, Uta, Watari and Kikuta which was given from Hitachi Province. Shineha was the present Naraha. Namekata and Uta were the present Soma. Watari was the present Watari, Miyagi. The area of the present Iwaki City was composed of Kikuta and Iwaki (岩城 or 磐城).