Climb the ladder

You climb the latter, which leads directly into the stone ceiling. This is different stone than the rough rock of the tunnel, though. The stone above you is smooth and carved with symbols you can't parse with only your fingers. On a hunch you brace your shoulder against it and push. Eureka, it moves! It's heavy as all hell but the tunnel is flooded with light as you heave the stone plate up and slide it aside onto the floor above you.

The room above you is vast and grand. The roof is peppered with holes, trickling in shafts of sunlight that illuminate the space. The room itself is bordered with a circle of tall stone pillars that support the ceiling.

The walls are carved with images very similar to the ones depicted on the tapestry, but far expanded. Beyond the cloth's scope villagers farm, fish, weave, and live their lives. At the center of everything is still that temple, still with that cloud above it.

In the middle of the chamber is a throne sitting atop a pyramid of steps. A statue sits regally upon the throne. At the statue's feet sits a small stone altar of some use.

The light catches something in the statue's lap, and your eye is drawn by the glitter of gold.

You hear a wet slapping from the hole you exited and hastily shove the stone weight back in place right before you hear something SPLAT against it. You're not sure how long it'll keep the swamp creature at bay, but you've bought yourself some time.