What is the best way to travel from Castlerotto to Varenna? We were hoping not to rent a car and use the train system. Thanks in advance for your help!
https://www.rome2rio.com will provide an overview of options
Simply reverse the trip that was described by Laurel in your other thread. When you reach Milano Centrale, buy a ticket on the Regionale train to Varenna-Esino. The trip is 1H:03M and very easy.