Use the raft to reach the island and then use your rope on a rock to reach the waterfall.
Return to the waterfall with the amulet and runes to complete the quest at the Chalice of Eternity. [Quick Guide] Waterfall quest The Waterfall
Since "The Waterfall" can refer to several popular topics, here are the most common guides to help you: Use the raft to reach the island and
Enter the tomb (bring no weapons or armor!) to get . 6 Air runes
Find in the Tree Gnome Village dungeon to unlock Glarial's Tomb.
1 Rope, 6 Air runes, 6 Earth runes, and 6 Water runes. Key Steps:
Talk to near the Baxtorian Falls (north of Baxtorian Outpost).