Built in: 1559 by Mori Terumoto
Before Tensho Era (late 16th century), Mori clan had their castle at Yoshida Koriyama. It was mountain castle. However, in that era, Mori decided to move their capital to current location because this place has wide space and large port. In 1589, Mori Terumoto built not only Hiroshima castle, but also he built great castle town and port for his Samurai of 1.2 million Koku.
To built this castle, Hideyoshi send Kuroda Josui to support Terumoto. Hideyoshi thought this castle would be very important for his war at Korea.
After the battle of Sekigahara in 1600, Terumoto lost most of his land and moved to Hagi, Fukushima Masanori became the lord of the land of Aki and Hiroshima castle.
After, Fukushima clan lost their land, Asano clan became the lord of Aki and he ruled from Hiroshima Castle.
Tenshukaku was very huge, but the interior was very simple. It remains until WWII, but burned down by the Atomic Bomb.
Current Tenshu was built in 1958. Top of the Tenshu is built from wood.