Unknow

Today i'll do this but i still need build every building (Main hall / big tower / garden / Bar and many other ) this look like this ( under the building is not load so you can see some white Blocks ) and this is the main trouble now , the water inside xD as you say the main of POI in game have air block so you can't put them under the water , but when you are inside this gonna be this i build this to see what happen when you are under the water with window , of course it empty but when every inch of the POI will be end it gonna be more nice to see at the window

Well i found a way with the POI, now all building will be under water and this is what i was looking for, but now when i'll go inside a building ( a little one because ) i'll have to remove the water with wood Blocks and next remove wood blocks to have air and this only on survie, when i stay in creative the water come back inside when it reload the city or i'll go far away. Do you have a picture of Air Blocks ? ( i don't found it )

Good Morning everyone (sorry for my english i'm french) I'm here because i want build a city under the water in pregen3 ( like rapture in Bioshock ) i wanna make a lot of building and area full of zombie, the player should clean if he want stuff and safe zone (and of course this should be only "world edit", like this i can share when the city is over) but... I got a lot of trouble making this town, i try Creative mod on the world but i can't build a city like this: every time i go away all building not saved are gone (and the save is only for one spot so i can't build a true city ) i guess i can't build this city with this way. Next i try build in prefabs mod but, when i go back in pregen3 and try put one building under the water, every time the tools is broken and turn all my building into a water... then i can't use this way too .... can someone help me ? it been 7hours i try start this city...