Parc Balbi is a public park beside the Orangerie, on the south side of the palace estate. It was originally the private garden of the Comtesse de Balbi, a favourite of the Count of Provence (Louis XVIII before his restoration), and was laid out in the English landscape style in the 1780s — a modest echo of what Marie Antoinette was doing at the Petit Trianon at the same time.
The park is free to enter and generally quiet. It makes a pleasant alternative to the crowded palace gardens if you want somewhere to sit in shade, eat a picnic, or let children run around without paying the garden entry fee. A few trees survive from the 18th-century layout.
The location — between the Orangerie and the Potager du Roi, just south of the main palace complex — makes it a useful stopping point if you are exploring the less-visited parts of Versailles. It is about 15 minutes' walk from the main palace entrance.