Grevenburg castle was built in 1350 by Count Johann III of Sponheim-Starkenburg and replaced Castle Starkenburg as the residence of the Rear County of Sponheim. With the extinction of the ruling male line of the Rhenish branch of the House of Sponheim in 1437 the castle became seat of the bailiff of the new Counts to Sponheim.
In 1680 it was conquered by Louis XIV of France and was extended, together with the fort of Mont Royal in the horshoe bend of the Mosel north of the town of Traben-Trarbach as a part of the fortifications. During the War of the Spanish Succession (1701–1714), in 1702 it was taken by the French under Taillardin and in 1704 on the express orders of the commanding officer John Churchill, 1st Duke of Marlborough it was overpowered by Friedrich das Wehrschloss. The badly damaged castle was then occupied by the Dutch. In 1730 it was repaired by the Electorate of Trier for the defence of Koblenz and the Rhine river. In the War of the Polish Succession it was taken after three weeks' siege for the fourth and last time by the French who destroyed it in July 1734. The castle was blown up, huge chunks of it have plunged into the valley beneath.
Of the castle, although only the western wall of the former keep remains, the foundations are largely intact.References:
Roman Walls of Lugo are an exceptional architectural, archaeological and constructive legacy of Roman engineering, dating from the 3rd and 4th centuries AD. The Walls are built of internal and external stone facings of slate with some granite, with a core filling of a conglomerate of slate slabs and worked stone pieces from Roman buildings, interlocked with lime mortar.
Their total length of 2117 m in the shape of an oblong rectangle occupies an area of 1.68 ha. Their height varies between 8 and 10 m, with a width of 4.2 m, reaching 7 m in some specific points. The walls still contain 85 external towers, 10 gates (five of which are original and five that were opened in modern times), four staircases and two ramps providing access to the walkway along the top of the walls, one of which is internal and the other external. Each tower contained access stairs leading from the intervallum to the wall walk of town wall, of which a total of 21 have been discovered to date.
The defences of Lugo are the most complete and best preserved example of Roman military architecture in the Western Roman Empire.
Despite the renovation work carried out, the walls conserve their original layout and the construction features associated with their defensive purpose, with walls, battlements, towers, fortifications, both modern and original gates and stairways, and a moat.
Since they were built, the walls have defined the layout and growth of the city, which was declared a Historical-Artistic Ensemble in 1973, forming a part of it and becoming an emblematic structure that can be freely accessed to walk along. The local inhabitants and visitors alike have used them as an area for enjoyment and as a part of urban life for centuries.
The fortifications were added to UNESCO"s World Heritage List in late 2000 and are a popular tourist attraction.