Rybník u Králova mlýna

Rybník u Králova mlýna is a small but ecologically remarkable pond lying north of Děčín, within the cadastral area of Maxičky, close to the German border. Covering just 0.6 hectares, this modest body of water was declared a natural monument in November 2000 — not for its scenery, but because of a plant once believed to be extinct in the Czech Republic.

Where exactly is the pond located?

The pond sits roughly 400 meters from the former, now abandoned settlement of Králův mlýn, from which it takes its name, and less than a kilometer from the state border with Germany. It lies on the Napajedla stream, which continues across the border as the Krippenbach and eventually flows into the Elbe near the German village of Krippen. The site sits at an elevation of about 365 meters above sea level, surrounded by forest typical of the Elbe Sandstone Mountains.

Where does the name come from and what is its history?

In German the pond was known as Königsteich, the "royal pond." It was created above the former Králův mlýn mill, which once stood along an old trade route leading toward Saxony. Although the mill and its settlement disappeared long ago, the pond survived, and its unusual water quality eventually earned it protected status.

Why is this pond protected?

The main object of protection is floating water-plantain (Luronium natans), a small aquatic plant that was considered extinct in the Czech Republic until 1999. During a floristic survey conducted that year, a surviving population was discovered in the waters of this very pond — a find that directly led to the site's legal protection the following year. Alongside the water-plantain, the pond also hosts other rare aquatic species, including amphibious bistort and bulbous rush.

What makes the water here so special?

The survival of the water-plantain depends heavily on water quality. The pond is fed by clear, cold water with a very low concentration of dissolved minerals. This kind of nutrient-poor yet crystal-clear aquatic environment has become rare in Central Europe, as most comparable ponds have been degraded by nutrient runoff and pollution from surrounding farmland or development. The pond's isolated location, away from intensive agriculture, has helped preserve these exceptional water conditions.

Who is responsible for protecting the site?

The natural monument is managed by the Nature and Landscape Protection Agency of the Czech Republic (AOPK ČR), through the administration of the Labské pískovce Protected Landscape Area. The site also falls within the protected zone for natural water accumulation of the Northern Cretaceous basin, which provides additional safeguards against development or activity that could threaten groundwater purity in the region.

Frequently asked questions

Can visitors swim or fish in the pond? Because the area is protected for its rare aquatic flora, the priority is to avoid disturbing the shoreline and water vegetation — it's worth checking on-site signage before considering any recreational activity.

Does floating water-plantain grow anywhere else in the Czech Republic? This is one of the few known sites in the country where the species has been confirmed after years of being presumed extinct, making the pond significant for the conservation of native aquatic flora.

How far is the pond from the German border? The state border lies less than a kilometer away, and the stream flowing out of the pond changes its name to Krippenbach once it crosses into Germany.