The town’s historical location was at the crossroads of the main routes through Livonia: the east–west route linking Rus’ with Western Europe, and the north–south route linking northern Estonia with the Latvian territories. The first mention of the settlement appears in the world atlas by the geographer Al-Idrisi, dated 1154. The scholar refers to the fortress of Viliende, which at that time belonged to the Estonians of the Skala tribe. This prehistoric stronghold was founded in the 9th century on Kaevumägi Hill (the site of the later main castle). The first attempt by Christian forces to capture it took place in 1211, but the siege proved unsuccessful for the crusaders. It was not until twelve years later that the Estonians were defeated. In 1224, on the orders of Volquin von Naumburg, Master of the Order of the Knights of the Sword, construction began on a stone order castle on the site of the captured stronghold; ten years later, it became the seat of the commandery (one of the six existing at the time). The stronghold at Felin was gradually expanded and eventually took on the impressive form of a model Teutonic conventual castle, consisting of a high castle (to the south) and two fortified outer bailey (to the north), situated lower down and also referred to as the middle castle and the lower castle. The oldest part of the upper castle was the mighty main tower, known as ‘High Herman’, to which a four-winged, two-storey convent residence was added on the south-eastern side, housing the most important monastic rooms: including, amongst others, the chapel, the chapter house, the dormitory and the refectory. The castle’s strategic location went hand in hand with the rapid development of the settlement, which had already been granted town privileges from the second half of the 13th century and became a member of the Hanseatic League in 1346. Poland’s ties with Felin began in 1582, when, following the signing of the Treaty of Jama Zapolska, the castle and town were occupied by the army of King Stefan Batory. Polish rule over the Livonian stronghold lasted less than twenty years, as the Swedes captured it in 1600. Two years later, the town was recaptured by the Poles as part of the Livonian campaign led by Grand Crown Hetman Jan Zamojski. However, this time too, it lasted only twenty years. As a result of the hostilities of the late 16th and early 17th centuries, the town was destroyed, and the castle fell into ruin and lost its military significance.

Modern-day Viljandi is a town with a population of around eighteen thousand, situated in the centre of southern Estonia. All that remains of one of the oldest and once most important strongholds of the Order of the Knights of the Sword are the picturesque ruins towering over the elongated stretch of Lake Viljandi (4.6 km long). The entire defensive layout remains clearly discernible; the topographical arrangement of the successive terraces and the moats separating them has been preserved, divided into the former upper, middle and lower castles. Among the surviving structural elements, one of the upper castle’s walls (the western wall), the remains of the castle gate, the lower part of the northern tower – known as the ‘Dansker Tower’ – and a section of the middle castle’s wall stand out. Some architectural features can be identified by the outlines of their foundations and a few small relics. The site of the former defensive complex now serves as a park for walks, whilst on the site of the former upper castle an amphitheatre with a stage has been built, where concerts and open-air events are often held in the summer. An additional attraction on the castle hill is a 50-metre-long rope bridge suspended over a 13-metre-deep chasm. The Art Nouveau red bridge structure was built by the Riga-based firm Felster & Co in the late 1870s. To the north of the castle hill, in the old town, stands the post-Franciscan Church of St John (now a Lutheran church). Built in the second half of the 15th century, despite partial reconstruction, it remains the city’s only surviving medieval monument. The church is a single-nave structure on an elongated rectangular plan, with a slightly narrower, also rectangular chancel enclosed on three sides. The main entrance leads through a square porch, which forms the base of a tall tower, crowned with a stylised cupola topped with a spire. The Old Town is home to the Municipal Museum, founded in 1878. Its current premises at 10 Johan Laidoneri Square are housed in an 18th-century building that formerly served as a pharmacy belonging to the Schöler family, which operated until 1940. The exhibition is divided into three sections devoted to: nature, archaeology, and the history of the town and the daily life of its inhabitants. Of particular value are the archaeological collections, which were assembled as a result of excavations carried out from the late 19th century onwards; these include, amongst other things, military artefacts from the Livonian Wars.