About 300 kgs of cannabis resin, eight kgs of cannabis herb and 1 kg of cocaine were found at Donaghmede Park, north Dublin, on Saturday at 19:30 local time.
The men, aged 25 and 52, were arrested at the scene.
They are being held at Coolock and Clontarf garda stations.
Two men have been arrested after Irish police seized drugs worth about 2.1m euros (£1.63m) in Dublin at the weekend.