Étang de l'Épinoche, Protected natural area in Montesson, France.

The Étang de l'Épinoche is a wetland in the Montesson Loop that spans about 6 hectares and consists of open water and extensive reed beds. The site sits within a larger protected park and provides different habitats for wildlife and plants.

The pond lies within the Boucle de Montesson departmental park and is listed in the ZNIEFF type I inventory of the Montesson ballastières under number 110001487. A study by the Île-de-France ornithological centre (CORIF) recorded 130 bird species on the site between 1984 and 1995.

The pond's two-hectare reed bed, the largest known in the Basse Seine valley, is what ornithologists come to study: a 1984–1995 survey by the Île-de-France ornithological centre recorded 130 bird species here, and 60 species nest on and around the water, 46 of them protected.

The pond lies within the Parc départemental de la Boucle de Montesson in Montesson, Yvelines, and is reached on foot through the park. The water's edge is lined with trees and shrubs, and about two hectares of reed bed grow on the site. Approach quietly and keep to the banks so as not to disturb nesting birds.

The site has become a refuge for rare bird species that are seldom found elsewhere in the Île-de-France region. These species use the different water and reed habitats to nest and rest during their travels.