Expo ’70 Commemorative Park (万国博覧会記念公園)

This sprawling park in the northern part of Osaka Prefecture once hosted the 1970 World Expo and has been maintained as a place for visitors to take a long walk in the park, marvel at artworks leftover from the expo (i.e. Tower of the Sun), visit the National Museum of Ethnology, or take a swan-shaped paddle boat ride in the Dream Pond. Other park facilities include The Japan Folk Crafts Museum, the Expo'70　Pavilion, and the Mori-no-Ashiyu (Forest Foot Bath). Keep in mind, additional admission is charged for some facilities.
Multiple playgrounds, funny bikes, and the wonders of the great outdoors will easily keep children entertained.
There is so much to do in the park, you could easily spend a whole day or more. Special events, like concerts, flea-markets, and expos are often held in the park near the East Entrance.
The park also includes a plum garden, which blooms in early spring, plenty of cherry blossoms throughout the park, sunflower fields in summer which are followed by an impressive cosmos showing in fall. The Japanese Gardens are stunning year-round as is the rest of the park.