Patras is Greece's third largest urban centre and the capital of the prefecture of Achaea, located in northern Peloponesse, 2 1 5 kilometers west of Athens. The city is built at the foothills of Mount Panachaikon, overlooking the Gulf of Patras.
The Patras metropolitan area is a conurbation of 222,459 inhabitants. The core settlement has a history spanning four millennia. In the Roman period it had become a cosmopolitan centre of the eastern Mediterranean whilst, according to Christian tradition, it was also the place of Saint Andrew's martyrdom. Dubbed Greece's Gate to the West, Patras is a commercial hub, while its busy port is a nodal point for trade and communication with Italy and the rest of Western Europe. The city has two public universities and one Technological Institute, hosting a large student population and rendering Patras a major scientific centre with a field of excellence in technological education. The Rio-Antirio bridge connects Patras' easternmost suburb of Rio to the town of Anti-Rio, connecting the Peloponesse peninsula with mainland Greece. Every spring, the city hosts one of Europe's largest and most colourful carnivals; notable features of the Patras Carnival include its mammoth-sized satirical floats and extravagant balls and parades, enjoyed by hundreds of thousands of visitors in a pleasant Mediterranean climate, with relatively cool yet humid summers and rather mild winters. Patras is also famous for supporting an indigenous cultural scene active mainly in the performing arts and modern urban literature; it was European Capital of Culture 2006.

The city is divided into the upper and the lower sections, connected with roads and broad stairs. The upper section is the older and the more picturesque; however, the lower sections are attractively laid out, featuring a variety of squares in a unique geometric pattern. The most notable of these are the Psila Alonia and the Georgiou I . A number of exquisite neoclassical buildings are to be found, including the '' "Apollon" Theatre in Georgiou I Square, the Town Hall, the headquarters of the Local Trade Association and the Court of Justice.
The most significant ancient monument, open to the public, is the Roman Odeon, now reconstructed and in use as an open-air theatre used for performances and concerts during the summer months. Over looking the whole town is the ruined Castle, whose current outline dates back to the Venetian invasion of the town (1 6 8 7–1715). Today, its interior is used as a public garden.

Near the seafront, between the sites of the new and the old port, stands the monumental church of Saint Andrew, the patron Saint of the city and the largest church of Greece] A replica of the city's emblematic old lighthouse, built as a part of a coastline beautification project, rises at a nearby park. In general, much of Patras' coastline is framed by roads and avenues running alongside; these include Dimeon Coast to the south and Iroon Politechniou Road to the north. Unfortunately, due to insufficient urban planning as well as institutional weaknesses on behalf of the City Council (mainly due to a lack of proper financial planning), some of the city's coastal areas are not in an ideal condition, with several areas illegally occupied by shops built along the coastline. This is contrary to what the Constitution of Greece of 2001 declares; that the Greek coastline is a "national treasure", and as such belongs to the Greek people
The Achaia region is home to 4 museums, including the Patras Archaeological Museum and the Museum for the Sacrifice of the people of Kalavrita. The Achaia Clauss wine tasting center is located on the outskirts in Petroto village. It was founded in 1861 by the Bavarian Gustav Clauss and is most famous for its Mavrodaphne. The winery is the main sponsor of the local basketball team, Apollon Achaia Clauss.
The region is also home to various Ancient Greek and Byzantine Monuments, including the Roman Odeum, the Castle of Rio and the Fortress of Patras

Patras is the first city of the modern Greek state to develop a city plan. In January 1829, Stamatis Voulgaris, a Greek engineer of the French army, presented the plan of the new city of Patras to the Governor Kapodistrias, who approved it. Voulgaris applied the orthogonal rule in the urban complex of Patras. The plan was divided into two sectors, the upper and the lower city, with a different city block layout; a revision of the proposal in 1858 was that finally realised.