Versailles

Versailles needs a day trip from Paris (40 minutes by train): the Palace and its gardens, with the Hall of Mirrors as the highlight, take up the whole day. April-June brings mild weather ideal for walking the gardens. It's somewhat cheaper than Paris as a day trip, though admission to the palace and gardens adds considerable cost. It was the residence of the French monarchy and a symbol of Louis XIV's absolute power, and its gardens, designed by André Le Nôtre, set the model for formal gardens later imitated by courts across Europe.