Some 500 ravers gathered at Skryne Castle, near the historic Hill of Tara, for an illegal party on St Stephen's Day night.
Castle owner Derek Iceton, 61, was forced to confront the revelers and break up the party.
Iceton told the Sunday World: "I started to get calls about 9pm on Sunday night to say the roads around Skryne were flooded with taxis and the people were pouring into the castle grounds.
"I contacted the guards before myself and the assistant farm manager, Ivan Clarke, went down immediately to see what was happening. To be honest my priority was to make sure our livestock, primarily the horses were safe, I assumed the guards would deal with everything else.
"However it became apparent the guards hadn’t arrived when we got there - so I went in and faced them down.
"The first thing I saw when I went in was a number of huge, two or three metre, canisters of nitrous oxide and also a massive bar that had everything from tequila to Cointreau for sale."
Nitrous oxide is a laughing gas which ravers put into balloons before inhaling it for a quick high.
Faced with crowds streaming in from every direction and hundreds more outside clamoring to get in, Iceton said he had to bluff his way in order to get some control over the situation.
"I started shouting that the Drug Squad and the ERU were outside and just about to raid the place, which of course they weren’t yet, but it worked.
"We blocked the main gate with a jeep which stopped the taxis that were still arriving from getting in but the people in them weren’t happy at not being admitted and the situation was fairly volatile until the guards eventually arrived.
"It was mayhem when we first arrived, I spoke to two girls who told me they had travelled from London for the gig which was headlined by a famous DJ.
"In fact he was that famous he had the audacity to ask me to book him a taxi to take him home.
"You can imagine what I said to that!"
The illegal event had been advertised via social media for a number of weeks, reports the Irish Independent.
The castle, which is advertised online, was rented at the time of the party.
The police were called, but Iceton feels that they were too slow to react to the situation. He said that he and his manager were left in a vulnerable situation trying to clear the property, and that the residents and businesses on the hill were also in a precarious situation.
“It is an old building,” he told the Meath Chronicle. “And anything could have happened – it was an extremely dangerous situation, to have hundreds of people who were not fully coherent in a premises with only one main door.”
A Garda spokesperson said: "An Garda Síochána responded to reports of an event in Skryne, Co. Meath on Sunday 26th December 2021. Gardaí attended and the crowd dispersed afterwards.
"Gardaí are investigating all the circumstances surrounding the event, no arrests have been made at this time."