Goa Kingdom is located on Dawn Island. We first saw this island during the flashback during the Post War Arc. It is home to the royal family and all the nobles.
This is the capital of the kingdom which is located on the ocean side and is surrounded by tall walls. Gray Terminal is just outside of the great gate and the kingdom is surrounded by Mt. Colubo. All of the trash and unwanted people are dumped in the Gray Terminal. The places in Gray Terminal are the Royal Family, High Town, Town Center, Edge Town, Great Gate, etc.
When they were kids, Luffy, Sabo, and Ace often came to the Goa Kingdom to eat and steal food or any other loot. They often ran through the streets to avoid the guards and the authorities. Sabo was born in the Kingdom and comes from there. Even though he was born into nobility, Sabo disliked nobles as he considered them heartless trash. He was ashamed to be born a noble.
When Sabo got to know that the Nobles had planned to burn the Gray Terminal down to impress the World Nobles and increase their social status, Sabo couldn't let the people of Grey Terminal be burned down so he sneaked out of his window at night to warn the people of the attack that was going to happen. But when he reached there, the area was already set ablaze, Sabo tried finding Ace and Luffy so that he could help them escape. Sabo was then spotted by some guards who went after him but he managed to hide from them. He then stumbled upon Dragon and said that the Nobles were trashy people and he was ashamed to be one of them.
After the time skip, Sterry married Sarie Nantokanette and became King of Goa, after the previous king died of mysterious circumstances.
The people who lived on the island are King Steery, Queen Sarie Nantokanette, Outlook III, Didit, Ahho Desunen IX, Yahoo Zurako, Monkey D. Luffy, Monkey D. Dragon, Portgas D. Ace, Sabo, Makino, Curly Dadan, Woop Slap, Porchemy, King of Goa, Didit, Bluejam, Sterry, Lord of the Coast, etc.
Dragon said the Goa Kingdom burning Gray Terminal is ‘a miniature blueprint for this world’s future’. Goa Kingdom shares its name with a state in India, Goa, which was under the rule of the Portuguese.
According to Luffy and Sabo, Dressrosa and Goa Kingdom are similar as both of these nations were under the rule of extreme class separation and discrimination that were caused by the upper class and nobles.
A. Goa Kingdom is located in East Blue.
A. Yes, Sabo is from the Goa Kingdom. He was a part of a noble family but detested them. He went to Gray Terminal to warn the people of what was going to happen to them.