The Kingdom of the Sea is the home of the SeaWings. It holds two palaces; the Deep Palace and the Summer Palace, and once held the Island Palace in Darkstalker's time. The Summer Palace was destroyed by an attack of Burn's forces due to Crocodile, a MudWing spy, following Webs into the palace and Blister tearing a hole in the protective canopy while trying to capture Webs. There are no known plans for the SeaWings to rebuild it. It was enchanted to grow out of the stone of the island by Prince Albatross, an animus dragon. It is unknown how far into the ocean the kingdom stretches. The location of the Deep Palace is unknown as the books did not state the exact location.
The Bay of a Thousand Scales is a spiral collection of islands which make up the "tail" of Pyrrhia (because it is shaped like a dragon). It is said to have thousands of them (hence its name), making it easy to hide the Summer Palace under a vast canopy there. It's a part of the Kingdom of the Sea and is therefore ruled by Queen Coral. Riptide meets the Dragonets of Destiny in the Bay of a Thousand Scales. Blister's Hideout was also located here and is mentioned to be spread across several islands to avoid an attack on the whole army. At the end of Darkness of Dragons the letter to Turtle said that Queen Coral was planning to make a reading area on one of the islands, and was going to make a palace open to all dragons from every tribe.
The Summer Palace was created by an animus SeaWing prince named Albatross around 2000 years ago, who grew the twelve-story pavilion out of stone before going insane and trying to kill everyone, specifically his family. More recently, the Summer Palace was reconfigured for Blister and the SandWings to visit more easily. The Summer Palace is hidden by a canopy, so no other dragon tribe had been able to locate it until the events of The Lost Heir. The idea of camouflaging the palace with plants was Prince Fathom's idea, as mentioned in Darkstalker (Legends).
At the end of The Lost Heir, the Summer Palace was discovered by the SkyWings and MudWings after Crocodile secretly followed Webs (Riptide's father) to the palace. Burn's alliance launched an attack that destroyed the palace. The SeaWings fled to the Deep Palace, where they stayed for the duration of the war, but Blister and her army still sent messengers to the ruins to see if there was any sign of her ally.
The Deep Palace is home to the Royal Hatchery and is the main headquarters of the SeaWing Royal Family. The palace is built underwater out of coral and stone, in the middle of a canyon.  The SeaWings prefer the Deep Palace because it is deep underwater and impossible to reach, stay in, or be attacked by the other dragon tribes. There was a statue of Orca with her talons outstretched benevolently in the wide front entrance of the Royal Hatchery. It was then destroyed by Queen Coral when it was discovered by Tsunami to be the mysterious assassin that murdered most of her daughters.
The only known function of the Island Palace was to host parties for ambassadors, which was shown in Darkstalker (Legends). On the map, the Island Palace appears to be slightly north of the Summer Palace. After the Royal SeaWing Massacre, it was mostly abandoned as many dragons were disturbed by the palace, thinking it was haunted. However, it was still used for the Talons of Power Ceremony. During Talons of Power, it was the location that Princess Anemone fought Prince Turtle. In the epilogue of Talons of Power, a spell was sent by King Darkstalker to haunt the Island Palace, leading to the SeaWings thinking that the spirit of Albatross had returned, this time to destroy all the SeaWings for good. In the epilogue of Darkness of Dragons, Prince Turtle reads a letter from Queen Coral, revealing that Turtle had successfully cast a spell to get rid of Darkstalker's fake Albatross ghost from the Island Palace and anywhere else on Pyrrhia.
- The Kingdom of the Sea is known to experience hurricanes more often than any other kingdom.
- The Deep Palace is incredibly well hidden and is still not shown on the map of Pyrrhia. The Summer Palace was only shown on the map in Moon Rising after Burn's army of SkyWings attacked it and burned it down.
- The Kingdom of the Sea has the most known animus dragons recorded so far.
Present: Abalone • Flounder • Herring • Herring's Brother • Kelp • Lagoon • Nautilus • Pearl • Piranha • Riptide • Snapper • Squid • Tempest • Tortoise • Urchin • Webs • Whirlpool