Twilight Princess Cave of Ordeals

[fisharox]

I am currently up to the sky temple but was bored so explored the desert and found the cave of ordeals. is this a must do later on or side quest?

 

[KillerHana]

Side Quest

50 level side dungeon !
There's a good reward if you complete all 50 levels, too

 

[Ghosi]

I advise you to do the Cave of Ordeals after you finish City in the Sky. Since you get an item from the dungeon, it is hard to finish it without that item. This is an optional sidequest of course, but if you are collecting Poes then you should finish it. As a reward for every 10 levels you complete, fairies will be released into one spring, and this will keep adding up.

 

[Master Sword13]

Agreed. Plus if you do it a second time, someone special will be waiting for you at the bottom. I'll put that in a spoiler tag for you.

Spoiler

The POSTMAN