Underground Structures

I'm wondering if it's possible to create structures, like a fallout shelter, that can be situated underground with access either through a elevator shaft or simply tp'ing. Are their restrictions on subterranean structures I should be aware of ?

Thanks

Avs can't go below the surface of the real terrain in sl, so if you want to do something like this you'll need to dig out a hole and place some kind or artificial terrain over the top.

Island land is typically 20 meters above the sea bed. Making a hole and covering it is simple if you have terraforming rights. The only problem is that the visibility is limited as the new structure is effectively underwater.

And yes you can put an elevator shaft or tp point to the bottom.

I have a sub-basement at the 0 meter level on island land which is about 20 x 30 meters and covered by 4 megaprims with grass texture on it.

Sounds like a good time for pretending to go down when we really go up to a skybox, as I don't need the actual visual of descending.

Thanks for the reply.

Paper.