Uranienborg (Uraniborg) was a Danish astronomical observatory operated by Tycho Brahe. It was built circa 1576-1580. Shortly after its construction the observatory was expanded with an underground facility, Stjerneborg, on an adjacent site. The building was dedicated to Urania, the Muse of Astronomy and named Uranienborg, "The Castle of Urania." It was the first custom-built observatory, and the last to be built without a telescope as its primary instrument.
The main building of Uraniborg was square, about 15 meters on a side, and built mostly of red brick. Two semi-circular towers, one each on the north and south sides of the main building, giving the building a somewhat rectangular shape overall. The observatory had a large mural quadrant affixed to a north-south wall, used to measure the altitude of stars as they passed the meridian. This, along with many other instruments of the observatory, was depicted and described in detail in Brahe's 1598 book Astronomiae instauratae mechanica.
A large wall, 75 meters on a side and 5.5 meters high was planned to surround Uraniborg, but never built, instead a high earth mound was constructed and lasted until today being the only remnant of the observatory still in place. Uraniborg was located in the very middle, with an extensive set of intricate gardens between the mound walls and the building. In addition to being decorative, the gardens also supplied herbs for the Tycho's medicinal chemistry experiments. The gardens are currently being re-created, using seeds found on-site or identified in Tycho's writings.
Uraniborg was an extremely expensive project. It is estimated that it cost about 1% of the entire state budget during construction.
Shortly after construction it became clear that the tower-mounted instruments were too easily moved by wind, and Tycho set about constructing a more suitable observation site. The result was near Stjerneborg a smaller site built entirely at ground level and dedicated purely to observations. The basic layout was similar to Uraniborg, with a wall of similar shape surrounding the site, although the enclosed area was much smaller. The instruments were all placed underground, covered by opening shutters or a rotating dome in buildings built over the instrument pits.
Upon losing financial support from the new king, Christian IV of Denmark, Tycho abandoned Hven in 1597 and both Uraniborg and Stjerneborg were destroyed shortly after Tycho's death. Stjerneborg was the subject of archaeological excavations during the 1950s, resulting in the restoration of the observatory. Stjerneborg now houses a multimedia show. The Round Tower in Copenhagen was inaugurated in 1642 as a replacement. The grounds are currently being restored.References:
From its origin as a small stronghold built by the ancient Illyrian tribe Dalmatae, becoming a royal castle that was the seat of many Croatian kings, to its final development as a large fortress during the Ottoman wars in Europe, Klis Fortress has guarded the frontier, being lost and re-conquered several times. Due to its location on a pass that separates the mountains Mosor and Kozjak, the fortress served as a major source of defense in Dalmatia, especially against the Ottoman advance, and has been a key crossroad between the Mediterranean belt and the Balkan rear.
Since Duke Mislav of the Duchy of Croatia made Klis Fortress the seat of his throne in the middle of the 9th century, the fortress served as the seat of many Croatia"s rulers. The reign of his successor, Duke Trpimir I, the founder of the Croatian royal House of Trpimirović, is significant for spreading Christianity in the Duchy of Croatia. He largely expanded the Klis Fortress, and in Rižinice, in the valley under the fortress, he built a church and the first Benedictine monastery in Croatia. During the reign of the first Croatian king, Tomislav, Klis and Biograd na Moru were his chief residences.
In March 1242 at Klis Fortress, Tatars who were a constituent segment of the Mongol army under the leadership of Kadan suffered a major defeat while in pursuit of the Hungarian army led by King Béla IV. After their defeat by Croatian forces, the Mongols retreated, and Béla IV rewarded many Croatian towns and nobles with 'substantial riches'. During the Late Middle Ages, the fortress was governed by Croatian nobility, amongst whom Paul I Šubić of Bribir was the most significant. During his reign, the House of Šubić controlled most of modern-day Croatia and Bosnia. Excluding the brief possession by the forces of Bosnian King, Tvrtko I, the fortress remained in Hungaro-Croatian hands for the next several hundred years, until the 16th century.
Klis Fortress is probably best known for its defense against the Ottoman invasion of Europe in the early 16th century. Croatian captain Petar Kružić led the defense of the fortress against a Turkish invasion and siege that lasted for more than two and a half decades. During this defense, as Kružić and his soldiers fought without allies against the Turks, the military faction of Uskoks was formed, which later became famous as an elite Croatian militant sect. Ultimately, the defenders were defeated and the fortress was occupied by the Ottomans in 1537. After more than a century under Ottoman rule, in 1669, Klis Fortress was besieged and seized by the Republic of Venice, thus moving the border between Christian and Muslim Europe further east and helping to contribute to the decline of the Ottoman Empire. The Venetians restored and enlarged the fortress, but it was taken by the Austrians after Napoleon extinguished the republic itself in 1797. Today, Klis Fortress contains a museum where visitors to this historic military structure can see an array of arms, armor, and traditional uniforms.