Fiumicino (FCO) & Ciampino (CIA) in Rome are the two closest airports. You can also fly into Pisa’s Galileo Galilei Airport (PSA) or Florence’s Amerigo Vespucci Airport (FLR), if required, however you should note that your journey to the retreat center will be 30-90 minutes longer.
Rome has two airports: Leonardo da Vinci (Fiumicino) and Ciampino. From either airport, you have to make your way to Termini Train Station in Rome. Trains leave frequently, however if you’d like to check train times and/or purchase tickets you can do that on the website here: https://www.trenitalia.com/en/purchase.html
From Fiumicino or Ciampino Airports: the cost of taxi is €200-260 if you make it straight from the airport to the retreat center. The trip will take roughly 2 hours.
From Pisa Airport: the cost of a taxi is between €300-350