in 1926. During World War II, a plant at Castrop-Rauxel used the Bergius process to produce synthetic () oil products. During World War II Castrop-Rauxel suffered 35 air raids and 24% of the city was destroyed by bombs. In 1961 Castrop-Rauxel had 87,910 inhabitants, its maximum in history. In 1975, the village of Henrichenburg was annexed and Castrop-Rauxel became part of the Recklinghausen (district). In 1984 the last of 7 coal mines at Castrop-Rauxel ("Erin") closed. As a consequence, the number of inhabitants declined. Sights Bladenhorst Castle (Wasserschloss Bladenhorst) was built in the 16th century. Saint Lambert Church, the oldest church in Castrop-Rauxel, stems from the 12th century. Another Saint Lambert Church built around 1450 in a late gothic style can be visited in Henrichenburg which became a part of Castrop-Rauxel in 1975. Goldschmieding Castle (Haus Goldschmieding) which was built in the 16th century was transformed into a hotel with a restaurant. The Town Hall was built from 1971 to 1975. The area of the former coal mine Zeche Erin was transformed into a park. Around the Market Place Altstadtmarkt several houses built in the typical style of Gründerzeit can be seen. During this period Castrop-Rauxel was a flourishing mining town. Mulvany, the industrialist who founded the first coal mine, had a race course laid out in Castrop in 1874. In 1912, a memorial was erected with a memorial fountain (Reiterbrunnen) referring to the horse races which were held until 1970. Parks Stadtgarten Park was laid out in the south of the centre in 1931. In the north of Castrop-Rauxel, Landschaftsarchäologischer Park Henrichenburg is worth a visit. It was laid out around the foundations of a castle which had been first mentioned in 1263 and dismantled in 1787. The foundations were rediscovered by chance during construction works in 1994. Ceramics, tiles and weapons were unearthened before the foundations were covered with earth again. Hedges were planted on the foundations to give an impression of the dimensions of the castle. Politics The current mayor of Castrop-Rauxel is Rajko Kravanja of the Social Democratic Party (SPD) since 2015. The most recent mayoral election was held on 13 September 2020, with a runoff held on 27 September, and the results were as follows: ! rowspan=2 colspan=2| Candidate ! rowspan=2| Party ! colspan=2| First round ! colspan=2| Second round |- ! Votes ! % ! Votes ! % |- | bgcolor=| | align=left| Rajko