Oh yeah... Forgot that you could do that. Just... Tunnel through at the adminium level and there you go... Hell, you could actually tunnel UNDER the adminium level. It has 5 layers, so bottom is ice, two air blocks and then the ceiling, with an extra adminium layer on top for good measure. Or maybe there should be adminium under the ice... Wouldn't want anyone to fall into the void.
Damn, it's a record! And I think I'll start planning out Venice in Creative. Or... I could just use a schematic of the REAL Venice. O.o