Halcyon's Pyramids

Halcyon's Pyramids, also known as the Undersea Palace of Halcyon or the Crystal Pyramids of Nafena, are a group of four interconnected crystalline pyramids in the seas North of Nafena. They are on a raised shelf that juts out of the deep ocean, and their tips just barely crest above the ocean surface.
The waters around the Pyramids are incredibly dangerous. The small raised shelf the pyramids sit on is thoroughly infested with Merfolk, including the legendary massive Siren known as Moksetar. Beyond the shelf, in the deep equatorial ocean, Leviathans prey on adventuring ships or groups of wayward Octofolk. The small local groups of sentient sharks are the least dangerous things around and the only things that won't attack on sight, though they generally avoid visitors.
The shelf approaching the pyramids is covered in shipwrecks, some of which are just barely visible from the surface. The local leviathans and sirens pile on as many of these broken ships as possible to lure in treasure hunters, with one particular leviathan (known as the Lurking Eyes) going so far as to drag other shipwrecks and treasures from the deep seas to the Palace for safekeeping. All things that go missing in the depths have a way of ending up here.
Those who manage to navigate their way to the remote location, survive the many surrounding dangers, and resist the temptations of the treasures below can look upon the pyramids in all their glory: no matter the weather, the waters around the pyramids are perpetually clear as glass. Each pyramid is a massive structure a little over 200 feet tall, and each extends into the ground. Around each pyramid's base is a massive stone platform, which overlap with one another. Broken stone columns and eroded statues litter these otherwise perfectly-cut foundations. 
Each of the outer 3 pyramids has two entrances: an aquatic entrance at the base, and a surface entrance at the pinnacle. The central pyramid has no entrances, windows, or cuts of any kind. All of the pyramids appear to be made of blue-white quartz, though the crystal is actually far more durable than any found in nature. Within the outer pyramids, visitors must travel through increasingly dangerous layers of puzzles, traps, and monstrosities towards the center. Each layer contains more air or water, forcing aquatic and surface explorers alike to prove their skill and versatility. Each challenge also includes treasure for those foolhardy enough to burden themselves with it. At the center of the outer pyramids are portals into the heart of the inner pyramid. Waiting for them at the heart is a great challenge, where air and water meet and explorers must fight in every possible way to stay alive. Survivors are gifted with a great boon: a permanent blessing to allow them to survive without air and in any pressure or environment. 
While folklore states that the pyramids are the personal residence of Halcyon, the pyramids were actually made by The Chimera.

History

Very few have seen the crystal pyramids, much less survived their trials. Most have been Cuttlefolk, whose curiosity and willingness to brave deep waters led them to the Pyramids many centuries ago. Few non-cuttlefolk understand their traditions fully, though - even other cephapeople don't understand their tales of explorers and adventurers past. 
Surface goers have discovered the pyramids many times, but it was only in the last century that they were actually placed on a map. Most mortals are more interested in the ship graveyard than the actual palace, as many artifacts of legend are trapped there: from Theia the Liberator's sword and crown, to Starmetal meteors, to great treasure galleons brimming with gold and silver, to magic items, the treasures surrounding the pyramids are a reward in themselves. Few would dare to actually try to invade the pyramids, and those who have do not return.
The great exceptions to this are the Immortals, as several have explored the pyramids and won their rewards. Most notable of these are the wandering godHaru and the immortal wizard Darza (who is also the one who properly mapped the location in 1943).

Founding Date

-100 DE

Type

Dungeon

Parent Location

Nafena