A vigil is set to take place overnight from tonight until tomorrow.
This will be hosted by the Somme Museum in Conlig, to the south of Bangor, and will start at 7pm with an act of remembrance.
A small group of veterans are then expected to maintain the vigil throughout the night.
At 7am tomorrow, a service of commemoration will be held, which the public are encouraged to attend.
However, seating is understood to be limited, and anyone hoping to attend is asked to contact the Northern Ireland WW1 Centenary Committee by emailing the following address: firstname.lastname@example.org.
The committee has described the gathering as a “national-level event”.
The location also holds a particular significance, because the 36th Ulster Division trained at the nearby Clandeboye Estate in the early part of First World War.
Tomorrow evening Carrickfergus will be hosting the Somme Centenary Festival of Remembrance – although this has now sold out.
Among those performing at the ticketed event at the town’s castle will be singer Aled Jones.
The evening will begin with a march organised by Armed Forces veterans organisations from across Northern Ireland.
The parade will form up from 6.30pm at the north end of Marine Highway in Carrickfergus and proceed to the castle.
The parade will enter the castle site at 7.28pm, something which organisers said has been timed to be exactly 12 hours after troops went over the top in France a century earlier.
Those at the castle will then be witness to what organisers described as an “emotional depiction of the Battle of the Somme”.
This will include military and orchestral music, plus drama performances and recitals, including reading of real letters sent from the trenches.
On Sunday at 3.30pm, St Anne’s Church of Ireland Cathedral at the north end of the city centre will host a Somme centenary service.
Attendance will be by invitation only, but to request attendence e-mail email@example.com .