Date Masamune, who relocated his castle from Yamagata Prefecture on the orders of Toyotomi Hideyoshi, lived in a castle here in Iwadeyama for 12 years up to the transfer of his administration to Sendai. The Iwadeyama Castle Site is currently maintained as a park. It is a place of relaxation for visitors. It overlooks the town of Iwadeyama.

Approximately 350 cherry trees (Yoshino cherry trees, weeping cherry trees and double-flowered cherry trees) bloom in full glory here from mid-April to late April. The area is packed with many people during the cherry blossom viewing season. Masamune Festival, which is held on the second Saturday and Sunday in September every year, recreates the appearance of this warrior who set off from Iwadeyama leading a large force of 3,000 men to proceed to the capital approximately 420 years ago. This is a heroic sight of brilliantly dressed horseback warriors and armored warriors blowing war horns. It is exactly like a moving picture scroll of the Sengoku (Warring States) period.