His body was found on concrete steps in North Street in the early hours of Sunday morning.
He was treated by medical staff but was pronounced dead at the scene.
Gardaí (Irish police) have appealed for information about the incident.

Not sure what we're on about? Australia has run through a slew of prime ministers in recent years and is holding a federal election on 2 July. You can read more about Australia's revolving-door of political leadership on these links, but for now, let us journey to Australis Minor.
Are Australians ready to gamble on yet another PM?  |  Coup capital of the democratic world
Laurent Sanguinetti is a French-Australian illustrator who bases himself between Sydney and Paris. You can see more of his work at his website.

The 35-year-old former West Ham and Derby man was approaching the end of his contract at the club.
Bywater, whose previous clubs include Millwall and Sheffield Wednesday, has not played for the Brewers since signing on a free transfer from Doncaster in January.
But he will continue to act as cover for first-choice keeper Jon McLaughlin.
"It's great news that Stephen is staying," Burton manager Nigel Clough told the club website.
"He works very well with Jon McLaughlin, providing us with experienced cover, and has been a very positive presence around the club since joining."
A man in his 50s has died after being seriously assaulted in Swords, County Dublin.
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On a far-off planet that's very much like Australia, strange creatures engage in a brutal battle for political domination, in this satirical cartoon from illustrator Laurent Sanguinetti.
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Veteran goalkeeper Stephen Bywater has signed a new one-year deal at Championship side Burton Albion.