The Site includes the eastern part of Lake Geneva and the natural part of the Rhône river delta, and features open water, reedbeds, marshes, and riparian woodland. Despite the loss of its natural dynamics since the containment of the Rhône, the Site remains an exceptional landscape. The Site is the most evocative remnant of the immense alluvial and marshy zone that occupied a large part of the Rhone plain, and with a surface area of 6,300 hectares, it remains one of the largest natural wetland plain areas in Switzerland. The Site is remarkable for the diversity of its environments, its flora and fauna, as well as its landscape value. It is also of fundamental conservation importance as it shelters a large number of rare and endangered species. It is a prime site for migrating, nesting and wintering birds. Human activities include conservation, agriculture, fishing, limited forestry, gravel extraction, and outdoor recreation. There is a birdwatching tower. The Site is adjacent to the small lakeside city of Montreux, which hosted Ramsar COP4 in 1990. The Site was extended in 2011 from its original area of 330 hectares.