The Brabbia Marsh Nature Reserve is the foremost wetland in the Province of Varese and one of the most important in Lombardy. It covers an area of 5 sq km between Lake Comabbio and Lake Varese, about 12 km from the provincial capital town of Varese. Since 1994 the area has been managed by LIPU (the Italian association for the protection of birds) on behalf of the Province of Varese.

The Reserve (240 m a.s.l.) forms part of the morainic hill area lying to the south of the provincial capital. When the Verbano glacier withdrew after the last ice-age it left a huge lake in the area now occupied by Lakes Comabbio and Varese. The shallowest part of this glacial lake, corresponding to what is now the Brabbia Marsh, emerged when the water level fell.  Extensive reed beds, wet woodlands of black alder (alnus glutinosa), and ponds covered with water lilies and water chestnut make the Brabbia a mosaic of different environments.

The Reserve is a prime bird sanctuary, with over 150 species present through the seasons. It is a major nesting area for water birds and a vital stopover site for migratory birds. Observation hides overlooking the ponds give a good view of unusual nesting species such as the Ferruginous Duck, Garganey, Little Bittern, Purple Heron, Water Rail, along with the more common Mallard, Moorhen, Little Grebe and Kingfisher. There is also a large number of birds of prey such as the Common Buzzard, Honey Buzzard, Western Marsh Harrier, Black Kite, Hen Harrier, and the extremely rare Osprey. The Brabbia Marsh also hosts the largest colony of Grey Heron in the province, with over 100 pairs nesting each year.

The part of the Reserve in the territory of the village of Inarzo gives free access to visitors every day of the year. The area offers trails, information panels and three observation hides – one on each pond – for photographers and birdwatchers. The Visitor Centre in the village provides a range of information. The Reserve also organises guided visits for families, workshops for children and courses, all designed to help you discover the natural beauty of the Brabbia.