The amphitheater in Windisch in the canton of Aargau is an amphitheater that was built in the first half of the 1st century AD in the immediate vicinity of the Roman legion camp Vindonissa. With an extension of 111 × 99 meters, it is the largest facility of its kind in Switzerland. It is classified as a cultural asset of national importance. The first systematic excavations took place in 1897, and a year later the plant became the property of the Confederation.
During the reign of Emperor Tiberius (14 to 37 AD), when the Legio XIII Gemina was stationed in Vindonissa, a first wooden amphitheater was built. The oval floor plan was 95 × 80 meters, the arena area itself being 73 × 58 meters. This results in a maximum capacity of 9'000 spectators. The northern half of the auditorium was designed as a wooden construction, the southern half included a rising slope. Around 45 AD, the plant was destroyed by fire.
After the Legio XXI Rapax had moved into the camp, around 50 AD, the stone structure with three concentric elliptical walls was preserved until today. The outer wall was 111 × 99 meters, the arena 64 × 52 meters. There was space for around 11,000 spectators, with the rows of seats at least in the upper ranks made of wood. The spectators reached the upper seats via the stairs of the outer wall and a central wall in the middle. Through the entrances to the west, east and north, the middle ranks were reached, on the north entrance and the lower ranks. The two entrances to the arena (each with double-leafed gates) were located in the longitudinal axis of the oval, in addition to eight small gates for the targeted driving of animals. Coin finds suggest that the amphitheater was used until the second half of the 3rd century.
In late antiquity, the amphitheater fell into disrepair. A certificate dated 5 August 1457 called Äcker in the "Berlisgruob"; This name can also be found in the city chronicle of Brugg from the year 1530. This is a derivation of the Middle High German Berolass-Gruoba (Bärenzwinger pit) - probably a vague memory of the animal fights held in the amphitheater. In 1577 the Bernese chronicler Thomas Schöpf wrote of "bearlinsgruoben amphitheatri", the first cartographic representation as "rudera amphitheatri" can be found in 1660 in a work by Hans Conrad Gyger. According to Franz Ludwig Haller, the ruin of the eastern gate is supposed to have stood upright in 1770, but then the walls were used as a quarry.
From May 1897, the student from Wädenswil Otto Hauser carried out the first systematic excavation on their own. In order to be able to finance day laborers and leases, in August of the same year he founded the company "Pro Vindonissa". Until December 1897 further excavations followed, in which the first walls came to light. Hauser immediately sold finds to collectors, which is why he soon came up against the resistance of local historians, who sparked a polemic in the press. Finally, in January 1898, the Confederation bought the entire property for 23,000 francs and entrusted the excavations of the "Brugg and its surroundings antiquarian society". Hauser was no longer allowed to enter the grounds and suffered another insult in 1906 when the Antiquarian Company renamed itself the "Company Pro Vindonissa".