Salnecke is one of the best preserved 17th century castles in Uppland. The first known owner of Salnecke was a judge Karl Ingeborgasson Lejonbalk. He sold the farm to the Skokloster nunnery in 1302. Later it belonged to Bo Jonsson Grip and the monastery of St. Clare in Stockholm. The monastery was the owner until 1460, when Salnecke fell to archbishop Jons Bengtsson (Oxenstierna).
After Reformation Salnecke became a crown property. Gustav II Adolphus gave the farm to the council Filip Sadler in 1626. After his death in 1641 Salnecke was given to Grissbach. The castle belonged to his family until 1730's. Salnecke was acquired by Klas Samuel Jonas Gyllenadler in the 1830s and it is still in his family's possession.
References:The Amphitheatre of the Three Gauls was part of the federal sanctuary of the three Gauls dedicated to the cult of Rome and Augustus celebrated by the 60 Gallic tribes when they gathered at Lugdunum (Lyon). The amphitheatre was built at the foot of the La Croix-Rousse hill at what was then the confluence of the Rhône and Saône.
Excavations have revealed a basement of three elliptical walls linked by cross-walls and a channel surrounding the oval central arena. The arena was slightly sloped, with the building"s south part supported by a now-vanished vault. The arena"s dimensions are 67,6m by 42m. This phase of the amphitheatre housed games which accompanied the imperial cult, with its low capacity (1,800 seats) being enough for delegations from the 60 Gallic tribes.
The amphitheatre was expanded at the start of the 2nd century. Two galleries were added around the old amphitheatre, raising its width from 25 metres to 105 metres and its capacity to about 20,000 seats. In so doing it made it a building open to the whole population of Lugdunum and its environs.