Mac's Tavern, the Old City bar and restaurant known for its ties to "It's Always Sunny in Philadelphia" stars Rob McElhenney and Kaitlin Olson, is closing after a 15-year-run on Market Street. In an Instagram post Monday afternoon, the bar part-owned by the comedy power couple thanked supporters but did not give a reason for the closure. MORE: Man who allegedly posed as ICE agent to rob Northeast Philly auto shop charged with false imprisonment "When we opened this bar, our hope was to create a welcoming, down-to-earth place where people could gather, share stories, laugh a little too loudly and enjoy a drink or two among friends," the bar said. "What we got was so much more: a vibrant, loyal and loving community that made Mac's Tavern feel like home — not just to us and the staff, but to everyone who walked through its doors." Attempts to reach the bar were not immediately returned on Tuesday, and the tavern's social media post did not say whether it has already shut down. Mac's developed a national reputation as a tourism hot spot in Old City because of its connection to the long-running FXX sitcom, whose fictional Paddy's Pub is set in South Philly, where McElhenney was raised. The relationship between the two bars appeared as a "Jeopardy" question last year. In more recent years, Mac's became a destination for soccer fans to watch Wrexham AFC, the Welsh soccer club McElhenney co-owns with Ryan Reynolds. Their FXX series "Welcome to Wrexham," which follows the club's rise through the tiers of the English Football League, has won eight Primetime Emmy Awards and has been renewed for a fifth season. Mac's also hosted promotional events for Four Walls Whiskey, the Irish-American blend McElhenney launched with "It's Always Sunny" co-stars Glenn Howerton and Charlie Day. The Mac's Tavern storefront at 226 Market St. has a history of bars, including the former Anthony's Olde City Pub and Skinner's Tavern in the years before Mac's opened. "Though Mac's Tavern may be closing, our gratitude to you will remain open — and overflowing — forever," the owners said.