High on a promontory of Luxembourg sandstone, the ruins of Larochette Castle dominate the valley of the White Ernz, a confluence of the river Sure. One can reach this promontory through a large farmyard protected by an earth fortification. The main castle, built of sandstone, is surrounded by a wall, mostly destroyed today. A deep ditch, partly of natural origin, cuts the castle in two. At the far end of the promontory, the ruins of several seigniorial mansions witness the quality of the architecture of this castle. Since its acquisition by the Luxembourg state in 1979, this historical part of Larochette has seen numerous restorations and valuations. Photogrammetical pictures taken at the purchase of the castle were completed by archeological studies still continuing. The Lords of Larochette are first mentioned at the end of the XII century, among others as banner carrier for the House of Luxembourg. At the end of the XIV century, 5 seigniorial houses stood inside the walls of the castle. The Hombourg Mansion was constructed around 1350 as the brothers Frederic and Conrad, Lords of Hombourg, married the sisters Irmgard and Mathilde of Larochette. The Crehange House was built around 1385. At the end of the XVI century however, the castle was destroyed by a fire and remained in ruins. The Crehange House, of formidable architecture, was restored from 1983 to 1987. The Hombourg Mansion is still being consolidated. Besides the restoration and consolidation, vast excavations took place all over the area of the castle. The results of this archeological founds will allow to complete the knowledge about the history of the castle. It seems as if the origins of the Lords of Larochette were in Ouren. They became very influent and, from the XIIIth century, they were the most true vassals of the Count of Luxembourg. The German Emperor Wenceslas even allowed the Lords of Fels to have their own money in 1402.