In Hamilton Township, Mercer County, we found plenty of Phillies fans, including one going to the game Saturday.
"My son is driving down right now from UMass to go to the game with us tomorrow," said Richard Nielsen of Hamilton.
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Phillies phans get ready for NLDS at Citizens Bank Park
But in this part of New Jersey, the Mets fans are around too.
"I've been scrolling past their posts on Facebook. I'm not interacting," he laughed.
But we found at least one place where Mets fans and Phillies fans are peacefully co-existing.
At Tommy's Tavern and Tap in Princeton, you'll find a mix of fans - even among the employees.
"I'm originally from Staten Island. I grew up a Mets fan my entire life," said bar manager and Mets fan Anthony Gomes.
"Hopefully there's more Phillies fans than Mets fans but that's TBD," said employee and Phillies fan Jordan Joseph.
They say it creates a unique atmosphere on game day.
"A lot of the people who work here at either New York fans or Philly fans so it's a lot of banter while we're working," said Joseph. "It's going to be really exciting."
Fans on both sides are excited but nervous.
"The Mets weren't supposed to get this far. So it's all just wonderful," said Mets fan Dan Wolsk of Princeton.
"I thought the Mets were going to lose but Pete Alonzo came up big for us and now we're moving on to face the Phillies for the first time ever in the playoffs," said Gomes.
"I think it's a great opportunity for Phillies to show what they can really do," said Phillies fan Steve Springer of Haddonfield. "Their pitching has been fantastic this year."