The castle was one of the three great mountain castles of Japan along with Kasugayama and Nanao.
The fortress was strategically designed to control the Hokkoku Kaido, a major trade route connecting Kyoto with the Hokuriku region.
The main keep and its associated structures were almost entirely razed following the defeat of the Azai clan by Oda Nobunaga.
Oichi, the mother of the famous 'Three Sisters of Azai,' lived here before the castle fell.
Excavations have revealed unique drainage systems and stone-walled terrace foundations that demonstrate advanced engineering for the period.
Odani Castle Ruins, located on Mount Odani in Nagahama, served as the primary fortress of the Azai clan during the Sengoku period. It was the strategic stronghold of Azai Nagamasa and the birthplace of his wife, Oichi, sister of Oda Nobunaga. The castle is historically significant as the site of a major siege in 1573 that ended the Azai clan's power and led to the destruction of the fortress. Today, the site consists primarily of stone walls, defensive earthworks, and foundation stones spread across the mountainside. It is designated as a National Historic Site of Japan. The layout preserves the complex mountain-castle architecture typical of the 16th century, featuring tiered enclosures and steep slopes designed for defense.
The view from the Honmaru (Main Enclosure) site provides an expansive perspective over the plain and Lake Biwa.
Wear sturdy hiking shoes, as the site requires trekking up steep mountain paths.
Bring insect repellent during the summer and autumn months as the trail is heavily forested.
Pick up a map at the Odani Castle Sengoku Museum at the base of the mountain before ascending.
Attempting the full hike in standard street shoes or during heavy rainfall when paths become slippery.
The mountain trails may be inaccessible during extreme weather; check local conditions for trail closures.
Stay on marked trails to protect the ruins and do not remove any stones or artifacts.
