Forge

The forge appears to be a Volcano of somesort, that seems to be an important part of the sburb sessions. It arrives on meteors that are cast to Skaia, and recurringly to the players' respective planets when the Reckoning begins.

It is yet unknown what purpose it serves, but it is quite likely very important.

Kids' Forge
Jade lives next to the kids' forge, and it will, most likely, transported to her planet, if/when she arrives to the medium.

Trolls' Forge
Kanaya lives next to the trolls' session's forge, and it was transported to the Land of Rays and ??? with her, when she entered the medium.