Red Port is one of the two routes to cross the Red Line when traveling on the Grand Line. Pappag made the first reference to it. It is the official passage built by the World Government to travel through either side of the Red Line.
One Piece Episode 882
The Red Port is the official, authorized route of crossing the Red Line. Nevertheless, the World Government’s approval is a requirement. There seems to be a cost to pass through the port. Those who are given the go-ahead must abandon their ship and buy a new one over the other side.
One port is located on each side of the Red Line. The ports are located behind Marine strongholds. Both the New World port and the Paradise station are located behind the G-1 Marine Base (formerly known as Marineford).
In the Red Port, only the Paradise port could be seen clearly so far. It appears to be built on two Yarukiman Mangroves, which give the land the same features as the Sabaody Archipelago, including the occasional presence of floating bubbles.
It has a number of small, cylindrical-roofed structures, at least one of which is a restaurant decorated in Chinese style. The World Government symbol is located behind the bowsprit of a big ship structure that is on its coast. It is surrounded by smaller ship ports.
The port has two enormous bubble-built boats called Bondolas that are used as lifts to travel between Mary Geoise and the top of the Red Line. The enormous Shirahoshi and King Neptune, as well as a number of other royals and their parties, can all fit within because they are big and strong enough to do so. Bondolas with the numbers “2” and “4” are written in the Paradise port.
The Red Port may have been first seen in Chapter 223, where Bartholomew Kuma and Donquixote Doflamingo arrive at a pier that is somehow associated with Mary Geoise.
Red Port is located on the Red Line.
Yes, Red Port is the official route built by the World Government to cross either side of the Red Line.