On the other side, an obsidian room large enough for a ghast to spawn but no larger, has a single 1X1X2 opening filled with soil and leading to another 2X2 tunnel (obsidian in case explosions make it through the soil barrier).
The roof of the obsidian room has a 1X1 opening filled with soil connected to another 2X2 tunnel, which connects to the obsidian tunnel.
The player can check the room for a ghast and kill it from above without risk, then enter the room from the other opening to retrieve the drops.
If monsters can go through it, HELL NO. Only with a redstone security system will I leave such a horrible thing in my house. I don't want ghasts swarming in my house, useful for whatever they'll drop, but risking death wouldn't be worth it...
If they can't, or Ghasts can't survive in the real world, then I'd love to hop in the portal and collect resources.
I wish that obsidian was easier to get though...
I think making the portal enclosed by a small room may not be enough to prevent ghasts from spawning, since the spawning algorithm might be based on range from the portal, not whether it's in the same room or not.
My portal room's going to be lined with obsidian (plus a window) and have TNT set up across the room, such that I can set it all off with one button press and kill anything inside. (Or, if the ghast goes and spits fire, that'll set it off too, to pretty much the same effect.) I might just have some murder-holes in the ceiling to drop TNT through instead. Of course, this all assumes explosions can hurt it...
Actually, can sand / gravel suffocate mobs like they can players? A torch trap might be a more affordable, more difficult-to-construct way of doing this.
The Meaning of Life, the Universe, and Everything.
I started a new world today and built a giant multistory tower with my portal on top, surrounded by glass so the giant jellyfish of doom can't spawn..... And yes.... I premade my portal..... Just the frame though.....