Pollentia was founded by the consul Qintus Caecilius Metellus in 123 BC in the strategic location between the bays of Pollenca and Alcudia. It was the most important city in the Balearics duing the Roman period and covered an area of 15-20 hectares.
This area suffered a devastating fire in the 3rd century AD, but the city was not depopulated, since the construction of a fortification in the fifth century AD has been documented in the same forum. In the following centuries, the Pollentia site was partially or totally unpopulated, with the Christian medieval population settling down a bit further north, in the present town of Alcúdia. Excavations, since the 16th century, but especially since the beginning of the 20th century, have occurred mainly in the area of Sa Portella (a residential district), Camp d'en França (the city forum and the tabernae), and in the Roman theater.
There is also a museum, the Museu Monografic de Pollentia in the centre of Alcudia (by the church) which displays many of the objects found on the site.References:
The Petersberg Citadel is one of the largest extant early-modern citadels in Europe and covers the whole north-western part of the Erfurt city centre. It was built after 1665 on Petersberg hill and was in military use until 1963. It dates from a time when Erfurt was ruled by the Electors of Mainz and is a unique example of the European style of fortress construction. Beneath the citadel is an underground maze of passageways that can be visited on guided tours organised by Erfurt Tourist Office.
The citadel was originally built on the site of a medieval Benedictine Monastery and the earliest parts of the complex date from the 12th century. Erfurt has also been ruled by Sweden, Prussia, Napoleon, the German Empire, the Nazis, and post-World War II Soviet occupying forces, and it was part of the German Democratic Republic (East Germany). All of these regimes used Petersberg Citadel and had an influence on its development. The baroque fortress was in military use until 1963. Since German reunification in 1990, the citadel has undergone significant restoration and it is now open to the public as a historic site.