From Dragon Mania Legends Wiki
“This Ancient Portal leads to the Outer Isles, a land of battles to win and treasures to claim.”
The Ancient Portal is a building in the game that allows the Trainer to travel from the Archipelago to the Campaign Map. Traveling is done by selecting the Portal and then pressing the button. Returning from the Campaign Map is done by pressing the X button in the top-right corner of the screen.
Upgrading is the process through which the Ancient Portal's level is increased, thus determining the base number of Battle Energy available for use on the Campaign Map. Upgrading the Portal costs a fixed amount of Gems per level. Select the Portal to begin the upgrade process. Tap the button, then the Instant Upgrade button to complete the process. Each time the Portal is upgraded, both the Portal Energy and the Arena Energy are replenished. The level of the Portal does not affect the 'base' amount of Arena Energy, as that amount is only affected by the Trainer's VIP Status.
The size of the Portal is 7x7 squares, regardless of its level, making it the largest movable building in the game. Additionally, the aspect of the Ancient Portal stays the same throughout each of its levels.
Relocation of the Ancient Portal can be initiated by pressing down on the building until the X and buttons appear below it. The portal can then be moved into any available space by tapping on the new location or dragging the portal into position. An arrow is displayed on each side of the Portal, during movement, indicating whether it can be placed in a given area. Gray arrows indicate when an area is not available. The arrows will change to green once the Portal is over a clear space. The Portal is then fixed into position using the button. The X can be pressed at any time to cancel the movement and restore the Portal to its original position.
Trainers of VIP Level 11 and above can switch between the normal aspect of the Portal and a golden variant . The Golden Ancient Portal serves no purpose other than as an aesthetic enhancement. This option can be used even when the VIP Status is not active.