According to An Encyclopedia of Gardening:
Villeneuve l'Etang, near Marne, was occupied before the Restoration by Marshal Soult, who is said to have been very much attached to it, and to have derived great pleasure from planting and altering the grounds. The park may contain up to 300 acres, which occupy two sides of a valley, through which runs a small stream.... The planting in the park has been done in...the English style.... The Duchess d'Angouleme, having coveted this place, obtained it with some difficulty from Soult; and she has the merit of having added to the house a large conservatory and an aviary, and also a dairy establishment and a poultry yard. Notwithstanding the duchess's desire for the place, we were (in 1828) informed that she passed only one night at it, during the whole time it was in her possession.Joseph Turquan, in his biography of Marie-Thérèse, describes her routine as follows:
At Saint-Cloud she would rise at daybreak, and passing by the guardroom, where the sentries turned out to present arms, stroll under the trees, enjoying the fresh morning air. Book in hand, her favourite spaniel running on ahead, a footman following a few paces behind, she would wander aimlessly along the scented paths, immersed in thought. The King did not care for Saint-Cloud, and seldom went there for more than a few days at a time. She did not find the repose she craved when the Court was in residence; on the other hand, had she gone there often alone, gossips would have been prompt to hint at differences among the royal family. These considerations led her to purchase the estate and castle of Villeneuve-l'Etang....doubtless she longed for a solitude in which she might dream of the peace of a life led apart from the glamour of the throne.When the duchess was exiled, she took the pseudonym of the "Comtesse de Marnes" in honor of the village near her beloved retreat. Many years later, after the death of Marie-Thérèse, Villeneuve-l'Étang was where Napoleon III and his empress spent their honeymoon. It eventually came to belong to the Institut Pasteur. The original chateau no longer stands.
She loved Villeneuve-l'Etang, and retired thither as often as her duties allowed. In memory perhaps of her mother's parties for children at the Trianon, she would invite the best pupils from Saint-Denis and Ecouan and throw her park open to their joyous sports. She presided in person at the tea party which brought a happy day to its close, and showed in her gracious sympathy the maternal instincts which lay dormant in her thwarted nature.