The Puerta de Alcalá is a Neo-classical monument in the Plaza de la Independencia in Madrid. It is regarded as the first modern post-Roman triumphal archbuilt in Europe, older than the similar monuments Arc de Triomphe in Paris and Brandenburg Gate in Berlin.
Puerta de Alcalá was a gate of the former city walls built by Philip IV. It stands near the city center and several meters away from the main entrance to the Parque del Buen Retiro. The square is bisected by Alcalá Street, although the street does not cross through the monument, and it is the origin of the Alfonso XII, Serrano and Olózaga streets. Its name originates from the old path from Madrid to the nearby town of Alcalá de Henares.
Madrid in the late 18th century still looked like a somewhat drab borough, surrounded by medieval walls. Around the year 1774, king Charles III commissioned Francesco Sabatini to construct a monumental gate in the city wall through which an expanded road to the city of Alcalá was to pass, replacing an older, smaller, gate that stood nearby. It was inaugurated in 1778.
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.