Osaka Castle is one of Japan's most famous landmarks and it played a major role in the unification of Japan during the sixteenth century. The main tower of Osaka Castle is situated on a plot of land roughly one square kilometer. It is built on two raised platforms of landfill supported by sheer walls of cut rock, using a technique called Burdock piling, each overlooking a moat. The central castle building is five stories on the outside and eight stories on the inside, and built atop a tall stone foundation to protect its occupants from attackers.

The castle grounds, which cover approximately 60,000 square meters contain thirteen structures that have been designated as important cultural assets by the Japanese government. 

Under the Meiji government, Osaka Castle became part of the Osaka Army Arsenal manufacturing guns, ammunition, and explosives for Japan's rapidly expanding Western-style military. During World War II, the arsenal became one of the largest military armories, employing 60,000 workers.[6] Bombing raids targeting the arsenal damaged the reconstructed main castle tower and, on August 14, 1945, destroyed 90% of the arsenal and killed 382 people working there.

In 1995, Osaka's government approved yet another restoration project, with the intent of restoring the main tower to its Edo-era splendor. In 1997, restoration was completed. The castle is a concrete reproduction (including elevators) of the original and the interior is intended as a modern, functioning museum.

The sprawling castle grounds were covered with cherry blossoms, food vendors, musicians and taiko drummers. Approaching the castle was a large mall -- Miraiza Osaka-jo -- where we stopped for ice cream and a short rest on one of the many benches. The mall contained many restaurants and souvenir shops and many of the staff wore ninja costumes.