Columbus Area:

Columbus Zoo
Olentangy Indian Caverns
Motorcycle Heritage Museum
Ohio Expo Center/Ohio State Fairgrounds

Sandusky Area:

Seneca Caverns
African Safari Wildlife Park
Cedar Point Amusement Park

There are many things to do and see in Central Ohio, 
in and around Marion:

Bluefusion Entertainment
Roller Skating
Mini Golf and Ice Cream 
County Parks 
Marion Visitors Bureau 
Drag Racing 
Big Island Wildlife Area - 5 miles west of Marion on Ohio 95 
Zane Shawnee Caverns
Harding Home and Museum  380 Mt. Vernon Avenue in Marion