- Type: Okinawan gusuku
- Status: Ruins
- Japanese: 伊祖城 (Iso gusuku)
Iso gusuku was a fortress located near Urasoe, in central Okinawa. It is said to have been the birthplace of King Eiso (r. 1260-1299), and is believed to have played a support role in managing Urasoe's maritime trade.
The fortress is a relatively small-scale gusuku, located about 1.6 km west of Urasoe gusuku, which was the seat of Okinawan kings before Shuri. It is unclear when it was built; according to the Omoro sôshi, it was built by Amamikyo, one of the creation gods in the Okinawan mythology.
Some of the stone walls of the fortress remain, outlining a number of enclosures. The gusuku's sites of worship are gathered together into Iso Shrine at the center, surrounded by walls of cut, stacked stone. The outer walls, meanwhile, especially to the southwest, are made of uncut, piled rocks. A high point at the northern end of the central enclosure may have been used as a lookout point - from there, one can see to Machiminato, the Kerama Islands, and Zanpa-misaki in Yomitan.
As at many other gusuku sites, celadons, porcelains, and other objects have been unearthed, suggesting the fortress' active involvement in trade.
- Kitahara Shûichi. A Journey to the Ryukyu Gusuku 琉球城紀行。 Naha: Miura Creative, 2003. p89.