Giant's Causeway cases the horizontal fracture has resulted in a bottom face that is convex while the upper face of the lower segment is concave, producing what are called "ball and socket" joints. The size of the columns is primarily determined by the speed at which lava from a volcanic eruption cools. The extensive fracture network produced the distinctive columns seen today. The basalts were originally part of a great volcanic plateau called the Thulean Plateau which formed during the Paleocene. According to legend, the columns are the remains of a causeway built by a giant. The story goes that the Irish
History of the Berlin S-Bahn ended on 1 January 1994, with the creation of Deutsche Bahn due to the merger between DR and the former West Germany's Deutsche Bundesbahn. All S-Bahn operations in Berlin were transferred to the newly formed S-Bahn Berlin GmbH as a subsidiary of Deutsche Bahn, and the BVG withdrew from running S-Bahn services. Technically, a number of projects followed in the steps of re-establishing broken links in order to restore the former S-Bahn network to its 1961 status after 1990, especially the Ringbahn. In December 1997 the connection between Neukölln and Treptower Park via Sonnenallee was reopened, enabling S4 trains to