Portal Hub

The Portal Hub is a small island near Training Grounds.
The Portal Hub consists of two islands, the main one which has a deactivated portal and an InfoTab, and the other which works as a path to the main island. It's closest to the Training Grounds, and that is it's intended path, though it can be accessed from The Dark One's Portal.

The portals on this island used to be completely inactive, but since 12/5/2020 the portals have become available to anyone who has completed the game -- making the Portal Hub accessible from any major location.

Appearance
The Portal Hub has a total of of 9 portals, having 4 portals on either side of the island and 1 large portal in the middle. However, the island technically only has 7 usable portals, as 2 are destroyed. Once completing the game, these portals will take you to any major location.

The 3 portals on the right will take you to the Windmill Plains, the Tower of the Sun, and the Forgotten Isles. The 3 portals on the left will take you to the start, the Desert Fortress, and Snowpeak Aquaduct. Finally, the largest portal will take you to the Great Shrine.