From Plochingen to Stuttgart, the Neckar valley is densely populated and heavily industrialised, with several well-known companies. Between Stuttgart and Lauffen, the Neckar cuts a scenic, meandering, and in many places steep-sided, valley into fossiliferous Triassic limestones and Pleistocene travertine. Along the Neckar's valley in the Odenwald hills many castles can be found, including Hornberg Castle and Guttenberg Castle in Haßmersheim; the now-mothballed Obrigheim Nuclear Power Plant and the active Neckarwestheim Nuclear Power Plant are also located there.