There will be even bigger celebrations by Drogheda's Dominicans in six years time when the order will celebrate 800 years of ministry on the banks of the Boyne
The illustration was done by the renowned Irish artist PJ Lynch and it took 1.5 million pieces to complete the mosaic.
Team of mosaic-makers from Italy are in Knock to assemble Irish artist PJ Lynch's depiction of the 1879 apparition.
