Paris Orly Airport - Aéroport de Paris Orly, can be found just south (12km) of Paris, France. It has flights from cities in Europe, the Middle East, Africa, the Caribbean, and North America.
Orly Airport has two terminals: west and south.
To continue your journey by train you will next want to go to Austerlitz station if taking the non TGV (around 2 1/2 hrs to Tours) or Montparnasse for the TGV (around 1hr 15mins to Tours) to the Loire Valley.
If you need to get to Austerlitz take the free airport shuttle bus to the Pont de Rungis RER C station. From there you can take a RER C train directly to Gare d'Austerlitz where you can catch a train to destinations within the Loire Valley.
For Montparnasse take an Air France coach (confusingly called 'Les Cars' - French for 'motorcoach' ). These run every 12 minutes from 6:00 am until 11:00 pm. Buy a ticket on the bus. A one way trip should cost around € 11.50.
It takes 30 to 45 minutes to get to Montparnasse railway station. The bus will drop you off outside the station, at rue du Commandant Mouchottes. From here you can catch the TGV to cities within the Loire Valley.
If you are staying in Paris before travelling on to the Loire Valley.......
By train is the fastest way to get to Paris city centre from Orly airport. On arrival after the usual clearances, take the Orly Val train from either Orly South (Sud) or Orly West (Ouest) terminal into Paris.
The train takes you to Antony station which is the terminus for the OrlyVal on the RER line B. You need to transfer to another train to get into central Paris. Your ticket for the journey should costs around €10.00. Your ticket will be valid on the Orlyval train, the RER, and the Métro.
Trains are from 6 a.m. until 11 p.m and the journey time into central Paris should be around 40 mins.
Tickets can be bought at the RATP booth in the terminal, then take the escalator to the train station. Keep your ticket with you throughout the journey. It will be needed for the turnstiles at Antony and to exit the RER.
For your return journey, you can buy a ticket through to Orly at any RER or Métro station.