No one had ever reached the summit of the Olympia Tree.
The highest point accessible to the citizens within the city was the Great Arena located at the top of the trunk. Beyond that, there were branches spreading in all directions, all part of the military's exclusive zone.
Due to the extremely irregular direction of the branches, there were no "subway elevators" characteristic of Olympia City. Instead, steps were constructed along the branches.
The three climbed the steps of the thickest branch and finally arrived at a rooftop terrace.
This should be the very top of the Olympia Tree, for the branches and leaves spread out in all directions were beneath their feet. The altitude they had reached was nearing five thousand meters, putting them in the "oxygen-deficient layer" where the air was thin.
Aske and Peggy were fine, but Thira, who lacked physical power, was already gasping for breath, showing slight symptoms of altitude sickness.
