Lost River is a great place to walk/hike! You can even take a boat tour in a cave!
If you are coming or staying a day after, Mammoth is an awesome park! Its about a 50 minute drive from Bowling Green.
If you are a Purple Toad fan, they offer 8 free tastings and many different options. It's kid friendly a great place to grab a drink.
Joseph and I have made countless trips to Chaney's since moving to BG! There is a massive playground outside and plenty of options for food and ice cream. It's worth the drive!!!