Complex sentence: The resort lies 30km from Borjomi and is located within the so-called Bakuriani Depression/caldera which was built up by the lava flows from the Mukheri volcano.
Split into simpler sentences: The resort lies 30km from Borjomi and is located within the so-called Bakuriani Depression/caldera. The present-day area of the town was built up by the lava flows from the Mukheri volcano.