The entrance into the Depths under Tobio's Hollow. The first time you go there, you enter a cutscene and appear below; but if you actually go back there, you can slowly descend into the Depths. It's a simple thing; but after a dozen or so chasms, I found it impressive they had a different way you could use to make it down there.

https://detroitriotcity.com/media/e51a1949275576b7b2091f0debb67a6b118a69c264ec341b05138f72ac1afa50.jpg