Aquincum was an ancient city, situated on the northeastern borders of the Pannonia province within the Roman Empire. The ruins of the city can be found today in Budapest. It is believed that Marcus Aurelius may have written at least part of his book Meditations at Aquincum.
It was originally settled by the Eravisci, a Celtic tribe. Aquincum served as a military base (castrum), having been part of the Roman border protection system called limes. Around AD 41-54, a 500-strong cavalry unit arrived, and a Roman legion of 6,000 men was stationed here by AD 89. The city gradually grew around the fortress, and after Pannonia was reorganised by the Romans in AD 106, Aquincum became the capital city of Pannonia Inferior. The city had around 30,000 to 40,000 inhabitants by the end of the 2nd century, and covered a significant part of the area today known as the Óbuda district within Budapest. Ruins from the old Roman settlement can be seen in other parts of Budapest as well, notably Contra-Aquincum. These Roman structures were, during the 2nd and 3rd century AD, the heart of the commercial life of the Pannonia province. The excavations show evidence of the lifestyle of this period. The most important monuments in Aquincum are the two amphitheaters the Aquincum Civil Amphitheatre and the Aquincum Military Amphitheatre built in the 1st century AD.
People living in the settlement could enjoy the achievements of the Empire, like central heating in the houses, public baths, a Mithraeum and palaces, as well as two amphitheatres, the Aquincum Civil Amphitheater and the larger Aquincum Military Amphitheatre for gladiatorial combats and beast fights.
Many historic artifacts from the city now appear in the Aquincum Museum. The museum exhibits a reconstruction of the hydraulic system, Roman houses and paintings that have been recovered on site. The ruins of a three-level aqueduct have been discovered around the city.References:
The city walls of Avila were built in the 11th century to protect the citizens from the Moors. They have been well maintained throughout the centuries and are now a major tourist attraction as well as a UNESCO World Heritage Site. Visitors can walk around about half of the length of the walls.
The layout of the city is an even quadrilateral with a perimeter of 2,516 m. Its walls, which consist in part of stones already used in earlier constructions, have an average thickness of 3 m. Access to the city is afforded by nine gates of different periods; twin 20 m high towers, linked by a semi-circular arch, flank the oldest ones, Puerta de San Vicente and Puerta del Alcázar.