The former Army barracks in Monaghan town is to be converted into an educational campus.
It will accommodate a primary and secondary Gaelscoileanna as well as a higher education institute.
The €20m project is expected to be completed within two or three years, although pupils will be using the sports facilities there within the next ten days.
While the gym, canteen and playing fields are likely to remain, most of the structures on the lands will be knocked down and replaced with school buildings.
Taoiseach Brian Cowen visited the 20 acre site earlier today for the official announcement.