The Mines

Ilsa goes mining here.

playing minecraft :) (episode 1)
The mines are shown in the house tour very briefly. The reason is because Ilsa doesn't like monsters and doesn't want to get attacked.

I went to the NETHER! :( (episode 3)
Ilsa shows her new mine. Then she says that she doesn't want to spend much time in them, because she doesn't want to fight a monster.

Trivia

 * It is possible that these are the same mines as the ravine where Ilsa got her first iron, and also saw her "neighbors".