There are 3 gates to enter, and the one on top of the waterfall brings you closest to the last boss.

There is a small skip you can do (discovered by me, and I'm sure others too) that skips you going around and climbing up the bridge the regular way. Simply jump up on the highest rock next to the bridge, and triple jump + backflip to get up on top.

Items used:

• Wearing: Lv70 full Mastery crafted Dragonflight gear, 3x Azerite Armor with the Longstrider trait, speed enchants
• Before entering: Fried Bonefish, Charged Phial of Alacrity
• During run: Nitro Boosts