Just an FYI: In case you noticed or are wondering how is it that the boulders in Sen's Fortress are able to go down two paths at the same time (1 - down the outside stairs, and, 2 - down the winding indoor stairs), it's because there seems to be some sort of trigger that turns the gears when you pass by the rooms that connect those two stairs...
![](https://i.ytimg.com/vi/kJrl0LOz_3A/maxresdefault.jpg)