The Château de l'Islette lies two kilometres west of Azay-le-Rideau, on the left bank of the Indre River. The Maillés, a high-profile family in the Touraine region since the 11th century, ruled over other châteaux such as Luynes, Plessis, Tours and Brézé. They acquired the Islette fiefdom in the 14th century. The first manor house was built around 1450 and expanded between 1520 and 1530 by René de Maillé. Following his death, the work continued under the direction of Charles de Maillé, Knight of the Order of St. Michael, and again during the 17th century.

The idea of a square layout set out around a courtyard and reinforced with corner towers was never carried out. The building consists of a main wing and a short wing set at right angles to the west. The short wing is the only part of the 15th century manor house still standing, its brickwork alternated with quoin-style chains of limestone blocks. The main wing stands three floors high and the façade is flanked by two massive round towers. This section and the towers feature horizontal cordons and are pierced with mullioned windows. While the symmetry may not be perfect, overall the search for order and harmony is evident. The main entrance is skewed towards the east: between the slits of an old drawbridge you can see the sculptured coat of arms of the Barjot de Roncée family, owners in the 17th century. Formerly there was a moat around the château. Some historians believe Azay-le-Rideau labourers were involved in the Islette project.

The château as we know it today has seen significant changes. In the 19th century the upper part of the building was demolished or altered, the dormers becoming battlements, the high roofs of the corner towers now candle-snuffer roofs, not to mention the moat.

The interior however retained its original organisation. The eastern corner tower houses the chapel, and access to the upper floors is via two spiral staircases. The sculptured and painted décor dates from the 17th and 18th centuries. Only the painted décor of the fireplace in the great hall dates back to the late 16th century.

In the mid-19th century Islette became a boarding house. The famous couple of sculptors Rodin and Camille Claudel, stayed and worked there in the 1890s.