The Sea Shrine is a temple on Earth that housed the Hourglass. Its first appearance was in "Steven and the Stevens". Within the episode, the Crystal Gems spend time inside it, finding the Hourglass. Steven however messed this up, causing the Sea Shrine to collapse, being saved by Garnet.
The Sea Shrine is filled with various hourglasses. If any hourglass other than the Hourglass is tampered with, the temple's ceiling disappears, and the temple will flood and be rendered inaccessible. This is shown when Amethyst grabbed the wrong hourglass in "Steven and the Stevens".
According to Pearl, the Sea Shrine reforms every 100 years after being flooded with water.
- According to Pearl, the Sea Shrine fell apart before "Steven and the Stevens" in one or more previous attempts of the Gems to locate the correct hourglass.
- In "It Could've Been Great", while Peridot talks about the colonization plans for Earth, schematics for the Sea Shrine are briefly seen on the Moon Base computer display.
- A concept map by Joe Johnston in Steven Universe: Art & Origins shows the Sea Shrine is located in the Caribbean Sea, just east of Hispaniola.
- The riddle of having to pick the correct hourglass among many different ones, or face dire consequences is a reference to the movie Indiana Jones and the Last Crusade in which the characters have to make a similar choice involving the Holy Grail.