The UN probably paid for the tunnels.
Israel is uncovering the 4th tunnel, but all that is mostly meaningless with the US pullout of Syria - the IDF will have to reorganize its units and plans to face the Iranian troops which can now come right up to the Golan border and Jordan’s border, and on top now have free access to the Med from Iran. Israel no faces an almost overwhelming existential military problem with this unplanned disaster.
Could Trump be pulling our troops from Syria to get them out of the way for Israel?
You can be sure the UN paid for these tunnels, probably complete with engineering drawings, component lists and instructions with a training program included in the package.