at the Naturschutzgebiet Siegaue, a protected area immediately to the northeast of the city of Bonn, near Niederkassel/Mondorf [de; ro]. The Sieg Spring...

the Sieg. It was the site of a fort during the Eighty Years' War and is now part of a protected natural area, the Naturschutzgebiet Siegaue. The Sieg originally...

monadnock made of quartzite, as well as the Malberg Conservation Area (Naturschutzgebiet Malberg). The Siebengebirge joining the range in the northwest near...

= square kilometres ND = natural monument NP = Nature Park NSG = Naturschutzgebiet (here: given with area and year designated) S = river source Mil trg...