Nature Reserve – Die Burg

The Burg nature reserve is located in the area of the towns of Marl and Recklinghausen in the Recklinghausen district in North Rhine-Westphalia.

The approximately 146 hectare area, which consists of four sub-areas, was placed under nature conservation in 1983 under the key number RE-011. It extends north of the core town of Recklinghausen and south of Lenkerbeck, a former farming community in the area of today's city of Marl. The A 43 runs along the western edge of the area, and the state road L 522 runs through the area in an east-west direction. The 60.5 hectare Loemühlenbachtal nature reserve extends to the west and the 0.9 hectare Silvertbachquelle nature reserve extends to the east.
(c) Wikipedia

The forest area Die Burg is a popular recreation area in Marl-Sinsen. In the Middle Ages there once stood an earthen castle whose ramparts are now completely overgrown by the forest. Paved trails lead through the 143-hectare nature reserve, which consists mostly of shady deciduous forest. The winding streams of Silvertbach and Nieringsbach that flow through the area are particularly impressive. Rare bird species such as the kingfisher have created nesting caves on their steep banks. Various amphibians such as common frogs, common toads or mountain newts find their optimal habitat in the neighboring ponds and silted up oxbow lakes

Here is some information:
kreis-re.de/contente/buergerservice/umwelt_und_tiere/umwelt/untere_naturschutzbehoerde/nsg_die_burg.pdf