Srebrna Góra Fortress – Donjon

Srebrna Góra Fortress is a unique 18th-century mountain stronghold located in Lower Silesia, towering over the mountain pass and the village bearing the same name. Considered the largest mountain fortress in Europe, it is renowned for never having been conquered during wartime. Its impressive fortifications and rich history make it one of the most fascinating military heritage sites in Poland.

Location and structure of the fortress

The fortress occupies the mountain peaks (686 m above sea level – Warowna Mountain and 627 m – Ostróg) above the Srebrna Pass (586 m), controlling a strategic passage between the Owl Mountains and the Bardzkie Mountains. The fortress overlooks the village of Srebrna Góra and once guarded an important route leading into the Kłodzko Valley.

Srebrna Góra Fortress was built between 1765 and 1777 on the order of King Frederick II of Prussia, shortly after Silesia was annexed by Prussia. Its purpose was to secure the newly acquired territory against potential Austrian attacks. At the time, it was one of the most extensive and modern fortifications in Europe. The fortress is part of a complex of six forts and bastions scattered across the surrounding peaks. Its central element is the massive Donjon – a four-tower fort connected by curtain walls up to 12 meters thick. The Donjon contains 151 casemates across three levels and served as the final defensive line.

The fortress included all essential facilities: food and ammunition stores, an armory, craft workshops, a chapel, prison, hospital, bakery, and even a brewery. This made it self-sufficient, with supplies intended to sustain the garrison for 3–5 months of siege. It could house around 3,500–4,000 soldiers, supported by 264 cannons and mortars.

Baptism of fire in 1807

Although the fortress was built with the Austrians in mind, its only true combat test came during the Napoleonic Wars. In June 1807, French troops under Jérôme Bonaparte, Napoleon’s younger brother, approached Srebrna Góra. The siege began – for several days the fortress was subjected to heavy artillery fire. Despite the bombardment, the fort held firm and was not captured. The siege ended after news of the Treaty of Tilsit (July 1807), which ended hostilities between Prussia and France. Srebrna Góra Fortress emerged from the ordeal unscathed – the only assault in its history had been repelled, and the title of an unconquered fortress has remained ever since.

Later history of the fortress (19th–20th century)

After the Napoleonic Wars, the fortress gradually lost military importance. By 1860, it was deemed obsolete, and in 1867 the last Prussian garrison left, closing its war chapter. For some time, it served as a testing ground – explosives and artillery were tested in its empty casemates. By the late 19th century, it became a local attraction – already in the 1930s, around 50,000 tourists visited it annually. At the base of the fortress, on the Srebrna Pass, a mountain cog railway station was built in 1900 to ease visitor access. Before World War I, a restaurant for 300 guests, a small arms museum, and a viewing platform were opened in the Donjon – the site’s historical and scenic value was already appreciated.

During World War II, the fortress gained a dark new purpose. From 1939 to 1941, two forts (Ostróg and Wysoka Skała) housed Oflag VIII B, a POW camp for Polish officers. Over 300 Polish soldiers were held here, including notable figures such as General Tadeusz Piskor, Rear Admiral Józef Unrug, and Commander Stefan Frankowski.

In the early post-war years, the fortress fell into ruin – looted by the Red Army and neglected by the new authorities. In 1966, a group of scouts from Lower Silesia began a civic preservation campaign (“Srebrna Góra Action”), cleaning up the site and opening parts of it to visitors. In 1974, a small museum of heavy firearms opened in the Donjon. Over time, restoration gained more support. In 2002, the Fortress Cultural Park was established to protect the entire complex. In 2004, the President of Poland declared Srebrna Góra Fortress a Historic Monument, recognizing its cultural importance to the nation.

The Fortress and the Village of Srebrna Góra

The connection between the fortress and the nearby village of Srebrna Góra is worth noting. Today a small village, it dates back to the Middle Ages – as early as the 14th century, it was a mining settlement extracting silver (hence the name “Silver Mountain”). After the silver ran out, the town declined, but the construction of the fortress gave it a new lease on life. In the 18th century, when Frederick II chose Srebrna Pass for his fort, the village became a typical garrison town – the presence of the military shaped the local economy and daily life for decades. During the siege in 1807, the town was heavily damaged by French artillery fire.

For years, Srebrna Góra lived in the fortress’s shadow, benefiting from the garrison’s presence. After the military left in 1867, the local population had to find new livelihoods. In the 1860s, several industrial plants were opened in the former barracks and surrounding areas (spinning mills, a tannery, a metal goods factory, and a pocket watch workshop) to repurpose the infrastructure and create jobs. Despite these efforts, the town lost its urban status – it became a quiet mountain village, which officially lost town rights after 1945 and gradually depopulated. Only the growth of tourism brought life back. Today, Srebrna Góra is thriving again thanks to visitors.

Interesting facts about Srebrna Góra Fortress

Largest mountain fortress in Europe: Srebrna Góra is considered the largest mountain fortress on the continent (spanning over 100 ha, with fortifications stretching 3 km). For comparison – it is significantly larger than the famous Kłodzko Fortress, which it was meant to complement in Silesia’s defense network. Due to its legendary strength, it is often called “The Silesian Gibraltar”, much like the British fortress in Gibraltar, considered impregnable.
Never taken by force: Despite the region’s turbulent history, Srebrna Góra Fortress was never stormed. In 1807, it withstood Napoleon’s forces (the siege ended with a truce), and no army ever attempted to take it again. It remained unconquered throughout the Napoleonic era – a rarity in Europe at that time.
Mighty Donjon: The fortress’s central Donjon is the largest structure of its kind in Europe. It consists of four round towers connected by 12-meter-thick walls, forming a vast inner courtyard. It houses 151 rooms (casemates) across three levels, including storage rooms, an armory, bakery, chapel, and hospital – a true fortress within a fortress, capable of withstanding a siege independently.
Self-sufficient stronghold: Designed to survive prolonged sieges without external supplies, the fortress had its own water sources (nine deep wells), ample food and ammunition storage, and facilities for the garrison’s needs (such as a brewery and bakery). These resources allowed up to 4,000 soldiers to endure sieges lasting up to 5 months. Interestingly, the deepest well (in Fort Ostróg) is 84 meters deep. According to legend, the cost of digging it equaled the cost of building the entire fortress!

Today, Srebrna Góra Fortress is a living monument and one of Lower Silesia’s top tourist attractions. After decades of preservation and renovation, most of its buildings are open to the public. Historical and cultural events take place here regularly – from battle reenactments to enthusiast gatherings and trail races. Daily guided tours let visitors explore the barracks, warehouses, and dungeons, see historic cannons up close, and even witness a live cannon firing. The fortress is continually evolving – it also houses a small hostel and tavern for travelers seeking a unique overnight experience.

3D Model – Photogrammetry for Archiving

I created a 3D model of the Srebrna Góra Fortress, which you can view on this page – Atlas 3D. The model was made from around 1,100 drone photos taken at an altitude of about 40 meters. This allows you to admire the entire stronghold from every angle – it’s a unique feeling to “fly over” this unconquered mountain fortress and peek into every corner of its majestic defenses.