The narrows at Drøbak, called Drøbaksundet, is a natural point for the naval defence of Oslo, the capital of Norway. The first defences were constructed during the reign of Christian IV of Denmark and Norway and were ready in 1644. The fortifications were however not involved in battle during the Hannibal War. After the war the fortifications were dismantled, and only resurrected for a short period during the 1814 war with Sweden.
Around 1830 the discussion started for a renewed fortification of the Drøbak Narrows and the first stage was ready in 1848, the next in 1853. The name of the fortress was given by royal resolution on 23 August 1855 after a visit by the Swedish-Norwegian King Oscar I.
By the end of the 19th century the art of war developed rapidly and the new fortress was soon obsolete. The tension was also growing between the two countries in the union and so the Norwegians decided to upgrade the fortress. From 1890 new improved German guns were installed, an underwater barrier was built in 1874–79, and an underwater torpedo battery was constructed. The main armament was three 28 cm calibre guns manufactured by Krupp. There were also a number of guns with smaller calibres on the mainland. An underwater barrier went from the main islet of Kaholmen and south-west to Hurum on the western side of the fjord, thus making it impossible for large vessels to sail west of the fortress.
Having been constructed in 1898–1901, and taken into service on 15 July 1901, the underground torpedo facility remained one of the few Norwegian defence installations unknown to German military intelligence at the point of the 1940 invasion. The battery was one of two in Norway and it was designed to launch its torpedoes from under the water level. At Oscarsborg the torpedo battery is a concrete construction inside a cave mined into the rock of the North Kaholmen island.
When Norway was invaded on 9 April 1940, all of the fortress' armament was over 40 years old, and of German origin. Both the guns and the torpedo battery worked flawlessly when Oscarsborg encountered one of the German invasion flotillas; they sank the heavy cruiser Blücher, and threw back the German naval force heading for Oslo, thus managing to save the Norwegian King and government from being taken prisoner. The fortress was returned to Norwegian control on 12 May 1945 when Captain Thorleif Unneberg took command of the fortifications and raised the Norwegian flag following the capitulation of all German forces in Norway four days earlier.
During the Cold War Oscarsborg formed a last line of defence for the capital city, with the underground torpedo battery remaining secretly active up until 1 January 1993, having been modernized in the 1980s. After the deactivation of the last weapons systems, the remaining military activity on Oscarsborg consisted of the Coastal Artillery officer training programme. The officer school was officially shut down in 2002. The fortress is now largely a civilian resort and attraction, open for visitors. The scenic surroundings is much used for conferences and excursions. Visitors take a short motor launch trip from Drøbak.References:
Heraclea Lyncestis was an ancient Greek city in Macedon, ruled later by the Romans. It was founded by Philip II of Macedon in the middle of the 4th century BC. The city was named in honor of the mythological hero Heracles. The name Lynkestis originates from the name of the ancient kingdom, conquered by Philip, where the city was built.
Heraclea was a strategically important town during the Hellenistic period, as it was at the edge of Macedon"s border with Epirus to the west and Paeonia to the north, until the middle of the 2nd century BC, when the Romans conquered Macedon and destroyed its political power. The main Roman road in the area, Via Egnatia went through Heraclea, and Heraclea was an important stop. The prosperity of the city was maintained mainly due to this road.
The Roman emperor Hadrian built a theatre in the center of the town, on a hill, when many buildings in the Roman province of Macedonia were being restored. It began being used during the reign of Antoninus Pius. Inside the theatre there were three animal cages and in the western part a tunnel. The theatre went out of use during the late 4th century AD, when gladiator fights in the Roman Empire were banned, due to the spread of Christianity, the formulation of the Eastern Roman Empire, and the abandonment of, what was then perceived as, pagan rituals and entertainment.
In the early Byzantine period (4th to 6th centuries AD) Heraclea was an important episcopal centre. A small and a great basilica, the bishop"s residence, and a funerary basilica and the necropolis are some of the remains of this period. Three naves in the Great Basilica are covered with mosaics of very rich floral and figurative iconography; these well preserved mosaics are often regarded as fine examples of the early Christian art period.
The city was sacked by Ostrogoth/Visigoth forces, commanded by Theodoric the Great in 472 AD and again in 479 AD. It was restored in the late 5th and early 6th century. When an earthquake struck in 518 AD, the inhabitants of Heraclea gradually abandoned the city. Subsequently, at the eve of the 7th century, the Dragovites, a Slavic tribe pushed down from the north by the Avars, settled in the area. The last coin issue dates from ca. 585, which suggests that the city was finally captured by the Slavs. As result, in place of the deserted city theatre several huts were built.
The Episcopacy Residence was excavated between 1970 and 1975. The western part was discovered first and the southern side is near the town wall. The luxury rooms are located in the eastern part. The 2nd, 3rd and 4th rooms all have mosaic floors. Between the 3rd and 4th rooms there is a hole that led to the eastern entrance of the residence. The hole was purposefully created between the 4th and 6th century.