Reaching the end of the Tunnel, that little legend about the Ignite Gem Cavern proved more as a fact. The light in the short tunnel just got stronger and stronger by the step... or crawl.
And the delicate purple glow as they've walked in the Cavern overwhelmed their eyesight, although not blinding them.
Their hearts became occupied with a bliss of accomplishment, although they've read about this Cavern just a little while ago.
This place is large and this time the two have it easy to comprehend a section's size as the Ignite Gems are providing light from one end to the other.
This is a rough guess here, but the Cavern has to be at least 300 meters long and 100 meters wide. That's just a guess, they have no way of properly measuring it.