For Kids:

1. Washington Park Botanical Garden: Free admission, beautiful gardens.
2. Lincoln Home National Historic Site: Free tours (tickets required).
3. Thomas Rees Memorial Carillon: Free concerts in Washington Park.
4. Illinois State Museum: Free for children 18 and under.

For Adults:

1. Abraham Lincoln Presidential Library: Free admission (museum has a fee).
2. Old State Capitol: Free tours of this historic building.
3. Lincoln Tomb: Free to visit this historic site.
4. Henson Robinson Zoo: Free for children 2 and under (admission for adults).

These free activities offer a range of experiences for both kids and adults in each city, from outdoor adventures and historical sites to cultural institutions and community events. Remember to check official websites for the most up-to-date information on hours, potential fees, and any restrictions.