Take the RER C (www.transilien.fr; about 40 min. from the Champs de Mars; Pont d’Alma, Invalides, St-Michel, Musée d’Orsay or St-Michel stations) to Versailles-Château–Rive Gauche. Make sure the final destination for your train is Versailles-Château–Rive Gauche and not Versailles Chantier, which actually runs in the opposite direction, touring all around Paris before arriving at Versailles, which will add an hour or so to your journey. Assuming you’ve taken the right train, it’s about a 5-minute walk from the Versailles Rive Gauche train station to the chateau—don’t worry, you can’t miss it. For a little more (4.45€ adults, 2.25€ ages 4–10), you can also take the SNCF Transilien suburban train (www.transilien.fr; 40 min.) from the Gare St-Lazare station to Versailles–Rive Droite, and then walk about 10 minutes to the chateau (around 50 min. total). This is a great option if you plan to picnic in the palace grounds, as you’ll go down Rue du Maréchal Foch, past a U Express supermarket (no. 45) and Marché Notre Dame, pl. du Marché Notre-Dame (daily 7am–7pm; outdoor stalls in the center of the square Tues, Fri, and Sun from about 9am to 2pm), where you can fill up on French delights. Glass is permitted in the park, so don’t feel you have to skimp on wine!
Unless you have a Paris Visite or other pass that includes zones 1–4, you’ll need to buy a special ticket for the RER C (one-way fare 3.65€ adults, 1.80€ children 4–10, free for children 3 and under); a regular Métro ticket will not suffice. Another option is to buy a one-day Mobilis pass for zones 1 to 4 (12.40€), which gives you unlimited travel in those zones for the day. You can buy a ticket from any Métro or RER station; the fare includes a free transfer to the Métro.
Note: This information was accurate when it was published, but can change without notice. Please be sure to confirm all rates and details directly with the companies in question before planning your trip.