Seosaengpo Castle is classified as a mountain castle, and is located in Korea. It is associated with the Toyotomi clan. Dates in use: 1593 - 1598.

Built at the beginning of Hideyoshi's six-year & ultimately failed campaign to overrun the Korean peninsular, it was also perhaps the strongest. Located atop a steep hill, it was protected by multiple rings of defence and further protected by cliffs & a harbour at its borders. This strong defensive position made the combined Korean/Chinese forces hesitant to attack.

Of the network of Wajō that lined the Southern & South-eastern coasts, there was just one further to the East, that of Ulsan. When Katō Kiyomasa received word that the Ulsan Wajō was under siege, he gathered a force & successfully relieved the castle, allowing them to safely withdraw from the castle & the war.

Timeline

1593	The castle was built by Katō Kiyomasa. 3,000 soldiers were stationed here.
1594	Records show that four rounds of peace talks were held here.
1597	Asano Nagayoshi was transferred here.
1598	Kuroda Nagamasa was stationed here along with a garrison of 5,000 soldiers. A short time later, following Toyotomi Hideyoshi's death, all Japanese forces were withdrawn from Korean peninsular & returned to Japan.
1895	The fortifications were decommissioned. For the previous 300 years or so, the old Japanese fortress had been used by the Korean navy as a base from which to defend against any threats from Japan.

Historical recognition

Site	8th Ulsan Monument