From the Wikipedia: "Antioch in Pisidia – alternatively Antiochia in Pisidia or Pisidian Antioch (Greek: Ἀντιόχεια τῆς Πισιδίας) and in Roman Empire, Latin: Antiochia Caesareia or Antiochia Caesaria – is a city in the Turkish Lakes Region, which is at the crossroads of the Mediterranean, Aegean and Central Anatolian regions, and formerly on the border of Pisidia and Phrygia, hence also known as Antiochia in Phrygia. The site lies approximately 1 km northeast of Yalvaç, the modern town of Isparta Province. [...] Antioch was a capital city for many different cultures because of the economic, military and religious activities of the region. This is the reason why Paul of Tarsus gave his first sermon to the Gentiles (Acts 13:13–52), and visited the city once on each of his missionary journeys, helping to make Antioch a center of early Christianity in Anatolia. The Emperor Constantine's liberalization of Christianity in 311 and the passing of new laws supporting it, caused people to adopt themselves to the new religion. Antioch played an important role as a metropolitan city at meetings of the church councils."

A notice at the gate gives: "Antiocheia is on a hill approximately 1236 m high and lies 1 km north of Yalvaç County of Isparta Province. The city is surrounded my the Sultan Mountains to the east, Karakuş Mountain to the north, Kızıldağ Mountain to the southeast, Kirisli Mountain and northern shore of Eğirdir Lake to the southwest. The acropolis of the citadel, which is surrounded by city walls, has an area of 47 hectares. The antique city was founded my Antiochus I from the Seleucid dynasty, between 281 BC – 261 BC and was called “Antiocheia”. Emperor Augustus, who established the first an greatest military colony in Pisidia, honoured the city with the title of Caesareia in 25 BC. The city became the capital of the region and a rich metropolis during the Roman Period. In the Early Empire Period the city was reconstructed on a new systematic plan, and many religious and secular buildings were built. The currently known buildings with the grid plan are the Augustan Temple, Theatre, Roman Bath, St. Paul’s Church, Central Church, Northern Church, Tiberius Square and Nymphaeum, besides these, Decumanus Maximus, Cardo Maximus, Western Gate and Propylon are also excavated at the archaeological site. St. Paul, one of the twelve apostles of Jesus Christ who played an essential role in the spreading of Christianity with his political identity, made three journeys from Jerusalem to Antiocheia, the capital of Pisidia. He lived there as a tent maker for two years. He taught Christianity by addressing the people of different faiths, and he preached Christianity from Antiocheia. All these factors further increased the importance of Antiocheia."

A word of caution: I used descriptions given on placards at the site. They tend to write in the present, describing how things would look when new. However, this was almost 2000 years later, so many things were in ruins.

Britanica Ansiklopedisi’nden: Antioch Pisidian, Yunanca adıyla Anticheia Pisidias, Pisidia sınırında, Türkiye’nin orta batısındaki modern Yalvaç’a yakın tarihi bir Frigya kentidir. I. Seleucus Nicator (MÖ 358-281) tarafından kurulmuş; MÖ 25’te doğrudan kontrolü ele geçiren Romalılar tarafından, MÖ 189’da özgür bir şehir haline getirilmiştir. Bundan kısa bir zaman sonra İmparator Agustus, Caesarea Antiochia adıyla burayı bir koloni yapmıştır. Burası, Güney Galatia’da sivil ve askeri yönetimin merkezi haline gelmiş ve İmparator I. Cladius (MS 41-54 yıllarında yönetmiş) zamanında; St. Paul, şehri, o bölgedeki misyonunun merkezlerinden biri yapmıştır.

Türkçe çeviri: Melek Emir. Katkılarından dolayı teşekkür ederim.