The Skypiea arc is the main story arc of One Piece's Sky Island Saga which takes place directly after the Alabasta Saga wraps up. It sees the Straw Hats look for a way to the sky to find a land where few have ever stepped foot on.
In the sky, two races rage war with one another as God Enel plans to eradicate everything for the sake of his goals. The Skypiea arc is very different from what fans are used to seeing in One Piece, however, there's more than one reason why it can be considered the best arc out there.
10 Nico Robin's Importance
Nico Robin joined the Straw Hat Pirates after Luffy saved her in Alabasta. Becoming a member of the crew, she takes on the role of their archaeologist and embarks on a journey with them to the sky.
Before Skypiea, Nico Robin's importance to the story wasn't really understood well. However, by the end of the arc, the hints about the Void Century and the Rio Poneglyph were revealed to the fans for the very first time.
9 Montblanc Cricket
Montblanc Cricket appeared in the Jaya arc of One Piece but his story continued as the Skypiea arc progressed. Cricket was shown to be a descendant of Montblanc Noland, a famous botanist from the North Blue who lived 400 years ago.
Noland claimed to have found the City of Gold, however, what he said was thought to be a lie and he was executed for it. Cricket, his descendant, was shown to be on a quest to find out the truth for himself.
8 Noland And Calgara
One Piece gave fans what could be considered as the best flashback in the entire story during the Skypiea arc. The story of Montblanc Noland, the famous explorer and botanist, was connected to the Shandians, specifically, Calgara.
After curing them of a deadly disease, Noland became great friends with Calgara, the snake Nola, and the Shandians and promised to return soon. Unfortunately, the Knock-Up stream happened to launch half of Jaya into the sky and to send a message to Noland, Calgara and his men kept ringing the fire of Shandora. Meanwhile, Noland was executed as the city of gold that he claimed to have seen and was now in the sky and nowhere to be seen.
7 The Winged Races
The Winged Races are an essential part of One Piece. Thought to have originated from the moon, these races came and eventually settled down in different places on Earth. The Skypieans lived on Skypiea, the Birkans lived on Birka, and the Shandorans lived on Jaya, which was eventually shot up in the sky.
These races are essential to the story of One Piece and Skypiea is the very first arc that introduces and explains them to us properly.
6 Shandora
One again, the Skypiea arc gave fans something incredibly important in Shandora. This city was known to be a prosperous one that existed over 800 years ago in the One Piece world. However, at some point, it fell at the hands of an enemy that it fought.
Shandora had its very own Poneglyph that the people had been protecting for years. It was the very first time that One Piece delved into what the Poneglyphs were and why they were so important to the story.
5 The Enemy Of The Ancient Kingdom
The Ancient Kingdom was a prosperous place that existed over 800 years ago in the world. However, at a certain point, all traces of it vanished.
During the Skypiea arc, fans get their very first hint of the enemy that the Ancient Kingdom fought since Shandora was ravaged by the same enemy.
4 Poseidon's Location
During the Alabasta arc, Nico Robin found the location of the Pluton that is said to be sleeping somewhere in the One Piece world. In the Skypiea arc, she was, once again, met with a Poneglyph that told the location of an Ancient Weapon, and this time, it was Poseidon.
Robin found out that the Poseidon was located 10,000 meters underwater on a place known as Fishman Island. After the two-year time-skip, the Straw Hat Pirates visited this place and met Shirahoshi, the girl who was born with this ancient power.
3 Lore
When it comes to lore, Skypiea is an arc that very few others can compete with. Everything about this arc was tied to the history of the world, the Void Century, the battle that was fought, and the enemy that they fought years and years ago.
Without a doubt, the Skypiea arc of One Piece is unbeaten when it comes to lore.
2 The Adventure
The Adventure of the Straw Hat Pirates has been incredible ever since it began and the world-building that Oda has pulled off with One Piece is spectacular.
Skypiea, due to its amazing location, world-building, and history is the peak of One Piece adventure. No other arc gives off the same sense of adventure as Skypiea.
1 Roger's Message
Finally, Gol D. Roger, the King of the Pirates, was revealed to have visited Skypiea a long time ago. This was later confirmed during Oden's flashback in chapter 966 of the manga.
Roger had Oden inscribe a message in the Golden Belfry that crossed over 20 years and reached Nico Robin, giving her a goal to find and deliver the Poneglyphs to the Final Island, Laugh Tale.