Srebrna Góra Fortress was constructed in 1765–1777 when the territory was part of the Kingdom of Prussia. The fort is one of Poland's official national Historic Monuments and has been declared a rare example of a surviving European 18th century mountain stronghold.
The fortress in Srebrna Góra was built by the order of Frederick II, the King of Prussia. It was designed by Prussian architect Ludwig Wilhelm Regeler, aided by a number of Prussian military engineers. Minor additional works took place in the following years, but no major alterations were made; construction of a nearby flanked fort was begun but was quickly abandoned. The complex is composed of six forts, several bastions, and associated elements. The main fort of the complex is the central Donżon Fort on the Warowna Góra hill.
The complex is located on the heights of the Sudety Mountains, a body which forms a natural border between the Kłodzko Valley and the Silesian Lowlands. It controls the passage through the Silver Valley (Przełęcz Srebrna or Silberbergpass). The fort could shelter a garrison of 4000 soldiers, supplied to survive a year-long siege. It was defended by 264 artillery pieces. The fortress was intended to guard a route linking Prussian territories with Bohemian lands in the south, and thus help repel any possible incursions from Austria.
The fortress was never captured by the enemy while besieged. On 28 June 1807 it successfully resisted a siege by Napoleonic forces during the War of the Fourth Coalition; this was the only time the fortress was the site of an active battle. By 1860 it was declared obsolete and the garrison reduced in size; it was abandoned as an active military stronghold in 1867. The fortress has survived till modern day with relatively little modernization or damage, contributing to its valuable status as a historical monument of its era. It served as a military training grounds, and by the end of the 19th century was already a tourist attraction, with a restaurant opened in the fort by 1885.
During World War II the fortress was used as a prison for Polish officers imprisoned by the Germans. In 1973 a military museum was opened in the Fort.References:
The Palace of the Kings of Navarre of Olite was one of the seats of the Court of the Kingdom of Navarre, since the reign of Charles III 'the Noble' until its conquest by Castile (1512). The fortification is both castle and palace, although it was built more like a courtier building to fulfill a military function.
On an ancient Roman fortification was built during the reign of Sancho VII of Navarre (13th century) and extended by his successors Theobald I and Theobald II, which the latter was is installed in the palace in 1269 and there he signed the consent letter for the wedding of Blanche of Artois with his brother Henry I of Navarre, who in turn, Henry I since 1271 used the palace as a temporary residence. This ancient area is known as the Old Palace.
Then the palace was housing the Navarrese court from the 14th until 16th centuries, Since the annexation (integration) of the kingdom of Navarre for the Crown of Castile in 1512 began the decline of the castle and therefore its practically neglect and deterioration. At that time it was an official residence for the Viceroys of Navarre.
In 1813 Navarrese guerrilla fighter Espoz y Mina during the Napoleonic French Invasion burned the palace with the aim to French could not make forts in it, which almost brought in ruin. It is since 1937 when architects José and Javier Yarnoz Larrosa began the rehabilitation (except the non-damaged church) for the castle palace, giving it back its original appearance and see today. The restoration work was completed in 1967 and was paid by the Foral Government of Navarre.