Ar is mentioned in the Bible

Bible

The Bible refers to any one of the collections of the primary religious texts of Judaism and Christianity. There is no common version of the Bible, as the individual books , their contents and their order vary among denominations...

 several times as a city of ancient Moab

Moab

Moab is the historical name for a mountainous strip of land in Jordan. The land lies alongside much of the eastern shore of the Dead Sea. The existence of the Kingdom of Moab is attested to by numerous archeological findings, most notably the Mesha Stele, which describes the Moabite victory over...

 . While the exact location is unknown, it was likely in the southern part of the Arnon Valley. The city was one of Moab's most prominent, being listed by the prophet Isaiah

Isaiah

Isaiah ; Greek: ', Ēsaïās ; "Yahu is salvation") was a prophet in the 8th-century BC Kingdom of Judah.Jews and Christians consider the Book of Isaiah a part of their Biblical canon; he is the first listed of the neviim akharonim, the later prophets. Many of the New Testament teachings of Jesus...

 in his denunciation of the Moabite nation .

The Bible

Bible

The Bible refers to any one of the collections of the primary religious texts of Judaism and Christianity. There is no common version of the Bible, as the individual books , their contents and their order vary among denominations...

 later speaks of Ar as being captured by the Amorite

Amorite

Amorite refers to an ancient Semitic people who occupied large parts of Mesopotamia from the 21st Century BC...

  King Sihon

Sihon

Sihon, according to the Old Testament, was an Amorite king, who refused to let the Israelites pass through his country. The Bible describes that as the Israelites in their Exodus came to the country east of the Jordan, near Heshbon, King of the Amorites refused to let them pass through his...

.

Modern scholars believe that the word "Ar" likely meant "city".