From BiblePortal Wikipedia

Fausset's Bible Dictionary [1]

A city of Asher given to the Levites of Gershom's family:  Joshua 21:30;  1 Chronicles 6:74. Hebron is substituted for it in  Joshua 19:28. Many manuscripts there read "Abdon"; the Hebrew letters Resh ( ר ) and Daleth ( ד ) are very similar, and therefore often interchanged.

International Standard Bible Encyclopedia [2]

ab´don ( עבדּון , 'abhdōn , perhaps "service"): One of the four Levitical cities in the tribe of Asher ( Joshua 21:30;  1 Chronicles 6:74 ). Probably the same with Ebron (in the King James Version "Hebron") in  Joshua 19:28 , where some copies have the reading Abdon. Now called Abdeh, a few miles from the Mediterranean and about fifteen miles south of Tyre.