The hilltop above Odawara has been fortified since the Kamakura period, when the Doi clan first recognized its strategic value controlling the approaches to the Kanto plain. But it was the Odawara Hojo clan who transformed a modest stronghold into one of Japan's most formidable defensive complexes. Beginning in 1495 when Ise Moritoki seized the castle from the Omori clan, five generations of Hojo lords expanded the walls, deepened the moats, and terraced the hillside into a layered labyrinth of stone, earth, and water. The castle's position was masterfully chosen: water-filled moats protected the lower approaches while dry ditches carved into the hillside guarded the upper flanks. Banks, walls, and natural cliffs completed the perimeter. This layered defense proved itself in 1561 when Uesugi Kenshin's forces broke against its walls, and again in 1569 when Takeda Shingen, one of the era's most feared commanders, was turned away. By the time Hideyoshi arrived with his enormous army in 1590, the Hojo had expanded their fortifications into a sprawling complex whose outer walls enclosed the entire town.

Hideyoshi understood that Odawara's defenses could absorb any direct assault. So he chose a different weapon: psychology. He ordered the overnight construction of Ishigakiyama Castle on a hilltop clearly visible from Odawara's towers, complete with stone walls and fortifications erected in a single night. To the stunned Hojo defenders, it appeared that Hideyoshi could conjure an entire castle from thin air. Meanwhile, his troops settled into a leisurely siege, entertained by musicians, performers, and markets that sprang up around the encampment. The message was unmistakable: Hideyoshi had resources and patience to spare. After three months, the Hojo surrendered. Hideyoshi awarded the entire domain to his most trusted general, Tokugawa Ieyasu, who would go on to unite Japan and establish the shogunate that ruled for 265 years. The castle was rebuilt on a smaller scale by the Okubo clan, fitting entirely within what had once been just the Hojo castle's third bailey.

If warfare shaped Odawara Castle's first centuries, earthquakes defined its later ones. The 1703 Genroku earthquake destroyed most of the castle structures; rebuilding the keep took three years and the outer works nearly two decades. The 1782 Tenmei earthquake inflicted further damage, and the 1853 Kaei earthquake struck yet again. Then came the Meiji Restoration of 1868, which proved more destructive than any tremor. The new government ordered all feudal fortifications demolished, and between 1870 and 1872, every structure at Odawara was pulled down. The bare stone foundations became the platform for a Shinto shrine dedicated to the Okubo lords. An Imperial Villa was built within the old baileys in 1901, only to be destroyed by the devastating 1923 Great Kanto Earthquake, which also collapsed many of the remaining stone ramparts. For decades, Odawara Castle existed only as rubble-strewn foundations and memories.

Odawara's resurrection began in 1950 when the ruined stone base was repaired and the grounds became a public park. A decade later, to celebrate the twentieth anniversary of Odawara's designation as a city, the iconic three-tiered, five-story donjon was rebuilt in reinforced concrete. Purists note that the observation deck crowning the tower was never part of the original design, added at the insistence of tourism officials eager for a scenic overlook. But the reconstructed tower gave Odawara its silhouette back. Subsequent decades brought more authentic restorations: a copper gate in 1971, the Akagane Gate in 1997, and the Umadashi Gate in 2009, each carefully researched. In 2015, the tower closed for a year-long seismic retrofit and exhibit modernization. When it reopened in April 2016, the city donated that day's entire admission revenue to Kumamoto, whose own famous castle had just been damaged by earthquakes. The Japan Castle Foundation recognized the reconstructed Odawara Castle as one of the 100 Fine Castles of Japan in 2006. Today the castle grounds hold a history museum, and each spring the moats fill with the reflections of hundreds of cherry trees in full bloom.

From the top of the donjon, the panorama explains everything about why this spot was fought over for centuries. Sagami Bay stretches south, its waters once patrolled by Hojo warships. To the west, the forested mountains of Hakone rise toward the volcanic ridges that sheltered hot spring towns even in the feudal era. The Tokaido road, the great highway connecting Kyoto to Edo, passes directly through town. Anyone controlling Odawara held the key to the Kanto plain and, by extension, to eastern Japan. Standing at the observation deck today, the castle's white walls gleaming above the tile rooftops, you can trace the same strategic geography that made this hilltop valuable to the Doi clan 800 years ago and that drew Hideyoshi's 200,000 soldiers to its gates.