L.L.
We like Centennial Beach in Naperville. Its run by the Naperville Park district and kids under 3 is free. You pay a daily admissions fee and there is a big sand area and a zero depth entry swimming area to swim in. Life guards are on duty as well as plenty of grass and shade with picnic tables to sit at. You can take you own cooler wit food and drink just no alcohol and there is a concession stand as well. The Children's Garden at the Morton Arboretum is also wonderful. Hope this help. L.