The Queen of England was due to visit the Rock of Cashel the day after the warnings were made, the court also heard.
Kevin Power, 38, with an address at Railway St, Passage West, Co Cork, has pleaded not guilty to membership of an unlawful organisation within the State styling itself the Irish Republican Army, otherwise Óglaigh na hÉireann, otherwise the IRA on December 19, 2011.
Yesterday at the three-judge, non-jury court, David Maher, a security officer at Cork University Hospital, told prosecuting counsel Vincent Heneghan BL that on May 19, 2011, between 1.55am and 2.05am, he received a phone-call warning of a bomb.
The caller, speaking in a Northern accent, said he was a member of the republican movement and that there were bombs at a UCC car-park and the Rock of Cashel, the court heard.
Mr Maher said after the warning he called the gardaí.
A volunteer with the Samaritans also gave evidence that, on the same night, at 1.59am, he received a call.
The caller said there was “an active device” at UCC and he gave the Samaritan volunteer a codeword, “Heather Bay”, the court heard.
Detective Sergeant William Blaney told the court that one of the warnings was about the Rock of Cashel and that he knew the Queen was due to visit the following day.
Earlier, opening the prosecution case, Mr Heneghan told the court that after the calls had been received and the gardaí contacted, UCC’s car park was searched and a detective found what he believed to be a grenade.
He said the evidence will be that the grenade was “non-viable” and for “training purposes within the army”. The court will also hear evidence the device had been put into a plastic bag and fingerprints were found on the outside on the bag.