réserve naturelle régionale de la forêt de Mequillet Le Hartwald

The Forêt de Méquillet "Le Hardtwald" Regional Nature Reserve stretches along the edge of the commune of Heiteren, in the Haut-Rhin department of France's Grand Est region. Covering roughly 250 hectares of forest and dry open habitats typical of the Alsatian plain, the reserve forms a narrow north–south band about 3 kilometers long and 1 kilometer wide across the southwestern part of the commune.

Where is it and how did the land take shape?

The Méquillet forest, also known as the Hardtwald, lies just south of Neuf-Brisach on a Rhine terrace built up by the river's ancient alluvial fan. That geological history shapes everything about the site: the ground is made of coarse alluvial deposits, with patches where conglomerate rock — pebbles cemented together with a limestone binder — breaks through the surface. Because water drains quickly through this coarse substrate, the topsoil stays dry and nutrient-poor, creating conditions that favor continental plant species rarely found elsewhere in Alsace.

Why is this forest ecologically significant?

The area was granted regional nature reserve status in 2012 specifically because of its rare combination of woodland and dry clearings. It's on these sun-exposed open patches that some of the reserve's most notable plants thrive, including the pasque flower — one of the first blooms of spring in this part of Europe — and the dittany, a plant known for releasing flammable essential oils that give it the nickname "burning bush." These species draw botanists and naturalists from across Europe who come specifically to study the dry, warm continental flora that survives here.

What is the history behind the site?

The forest's name traces back to the Méquillet family, its historical owners, whose estate once covered this land. At some point the property passed by bequest to the Protestant consistory of Colmar, a transfer that shaped how the land was managed and safeguarded long before it received formal recognition as a regional nature reserve.

What should visitors know before going?

Located in the commune of Heiteren near Neuf-Brisach, the reserve sits in an easily accessible part of Haut-Rhin. It appeals most to visitors interested in botany and rare plant spotting, as well as walkers looking for a stretch of relatively untouched natural landscape on the Rhine plain. Because the dry clearings host sensitive, protected species, visitors are encouraged to stick to marked paths, particularly during the spring flowering season.

Frequently asked questions

Where exactly is the reserve located? In the southwestern part of the commune of Heiteren, in the Haut-Rhin department, south of Neuf-Brisach.

How large is the protected area? About 250 hectares of forest and dry open habitats.

What makes this reserve special? Rare plant species tied to sun-exposed dry clearings on conglomerate rock, including the pasque flower and the dittany.

Since when has it held regional reserve status? Since 2012.

Where does the name Méquillet come from? From the family that historically owned the forest before bequeathing it to the Protestant consistory of Colmar.