Places to visit near Tallinn

Hello people, I am visiting tallinn for 2 days end of this month, I have been to Tallinn city many times, I would like to visit some nature this time, Any place near Tallinn which is nice ? I have heard about swamps. Also if there are any nice lakes where you can swim.

Would be great if accessible by public transport. I dont know how expensive or easy it is to rent a car in Tallinn.