The nearest destination you can go from Jim Corbett National Park are:
1. Nainital : Its a very good hill station around 60kms from the National Park.
2. Ranikhet : Its also around 80kms from the national park.It has some old temples.
3. Delhi : Delhi is around 250 Kms from the national park,you can always explore the capital of the country.
4. Dehradun : Its also 3-4 hours from the place.Its the capital of the state Uttarakhand.