Bahamut's Temple, otherwise known as the Dragon King's Temple, is a holy place in ancient Pulsian legend. It is said that the temple was the final resting place of Bahamut after he turned his back on humanity.
And the gate opens by Tonyholmsten

The final stage of Bahamut's Temple.

Guardians and Trials

It is said that any who make it through the traps and trials that litter the temple will be blessed with an audience with Bahamut himself. But there are said to be four guardians who protect the temple, to keep those with impure intentions from entering the resting place of the King of Dragons.

It is unknown what creatures, if any, actually guard the temple, but Pulsian legend also speculates that two of the fours guards are Tiamat—whom Bahamut saved from death—and Tyrasca—who is said to have guided and protected the Dragon King since creation.