Perugia- 45 minutes approx
Rome Fiumicino- Easyjet, BA, (approx. 2 hours)
Pisa - Easyjet, BA, (approx. 2 hours)
Florence - (approx. 1 hour & 30 mins)

The A1 Autostrada del Sole (Sunshine motorway) connects Rome and Florence, exit at Chiusi if coming from Rome, and at Val di Chiana if coming from Florence or Pisa.
From Val di Chiana take the SS73 in the direction of Perugia, exit at the sign for Castiglione del Lago. From Chiusi follow signs to Trasimeno on the SS71.
There is a railway line from Perugia to Terontola-Cortona, it passes to the north of lake Trasimeno with stations at Passignano sul Trasimeno, change at Terontola to get to Castiglione del Lago, this is the main line between Rome and Florence, stopping at Castiglione del Lago. You can purchase train tickets from Bar Alise opposite the Castiglione station, you must stamp tickets on the platform before departure