The National Museum of Japanese History is a good place to attain a comprehensive familiarization of Japan's history and culture. Opened in 1983, the museum also houses the School of Cultural and Social Studies, devoted to the advancement of the understanding and dispersion of Japan's history through research an study. The museum features both permanent and traveling exhibits, and in the past, has included such themes as Japanese poetry, and the meanings of shrine and temple illustrations. The museum is located in Sakura City.

The National Museum of Modern Art in Kyoto has been around since 1963, and focuses on the art of Japan's 20th century, specifically Japanese-style paintings and crafts.

The Osaka Maritime Museum is a unique place that celebrates Japan's seafaring past. Visitors enter the museum through an onshore , dome-shaped building that houses the typical tourist-oriented accoutrements - restaurant, souvenir shop, etc., then walk under the bay to the actual museum itself. There's a theater, a replica of a 17th-century trade ship, figurehead and nautical art exhibits, and more. 

Will it go round in circles? Yes. Will it fly high, like a bird up in the sky? Uh-huh. That is, the ferris wheel on the roof of the Hep 5 Mall on  Kakuda-cho. Take a ride on it at night and get a view of Osaka city lights. 

And don't forget Osaka Castle!