This is fairly basic glass structure that can be used underwater or anywhere really.

There are 5 structures. small x1 medium x4 and large x32 made from glass cubes with a diamond floor. The large one has a railway inside.

There are 2 glass tunnel structures small x1 and large x4 size. There is an area where you can make a tunnel entrance or join on the tunnel sections to make an entrance/exit. The glass tunnels look cool underground as well.

The .zip file has all 5 schematic files.

This is my first project hope you like it.

Comments welcome!