Stairs

Stairs are objects which appear in nearly every Zelda game. Generally, stairs separate one floor of a house, cave, or dungeon from another.

Collapsible Stairs
Collapsible stairs appear in Dragon Roost Cavern in The Wind Waker and in Hyrule Castle in Twilight Princess. They will fall if Link touches them. The expanded stairs stay and never fall.

Trivia

 * Starting in The Wind Waker and continuing into later console games, Link will walk on each individual step of a staircase.