Cruinniú na nÓg kicks off today with events taking place right across the region.
It's part of a national day of free creativity for children and those aged under 18.
There are sculpture, lantern making, and comedy workshops in County Roscommon.
County Leitrim will play host to puppet shows, aerial and circus workshops and archaeology.
Lego making is one of the highlights in Co Longford, where a sculpture of St Mel's Cathedral will be unveiled.
It was created by Ireland's only professional LEGO artist Jessica Farrell, who explains the inspiration behind it: