The Ancient Tomb is the eighth and final dungeon in Oracle of Ages. It is located in the midst of the Sea of No Return, and Link can only enter it after first obtaining a Tokay Eyeball from Captain and traversing a maze of stone. The dungeon sports four floors; 1F, B1F, B2F and B3F; making it one of the largest dungeons in the game. Midway through the dungeon, Link faces off with the miniboss, a Blue Stalfos. At the end of the dungeon, Link does battle with the boss, Ramrock. Link obtains a Heart Container, as well as the Falling Star, the eighth and last of the Essences of Time.
"The eternal light of this heavenly body acts as guide to the other essences."
The Falling Star is the last of the Essences of Time, and its description gives insight as to what its true purpose is. Not only is it the final essence obtained, it also serves as a guide to the other essences, perhaps by it being the foremost and maybe even the most important of the essences.