Bethsaida, along with Banias/Caesarea Philippi (both cities Jesus was written to have visited in the Gospel of Mark) is mentioned by Josephus as being transformed into a city called Julias by Philip the Tetrarch. The city is said by Josephus to be near the Jordan. Here is the site plan. Here is the coin report. The report indicates that most of Bethsaida’s coins came from Tyre and Jerusalem. Though there are fewer coins from the 1st C CE than from either the 2nd C CE or from the 1st C BC, five coins of Philip the Tetrarch and two coins of Antipas have been found at Bethsaida. Some Achaemenid coins were also found at the site. Bethsaida was apparently abandoned sometime in the fourth century AD, though was lightly reoccupied in the sixth.
Incidentally, Mark 6 makes no sense as it is; Mark 6:45 states Jesus intends to go to Bethsaida, but in Mark 6:53, Jesus winds up at Gennesaret! Bethsaida is next mentioned in Mark 8:22. Thus, some have, remembering the Gospel of Luke does not use the Bethsaida section, proposed the hypothesis that the whole “Bethsaida section”, as the section between Mark 6:45 and 8:22 is called, is an interpolation.