Gulf of the June Star, Ancient Crater
Millennia ago, there was war. Portals of countless number appeared everywhere across the world. From them, the Elementals sought conquest; their natural affinity to various aspects of the material plane led to earth elementals ambushing from below, water elementals sieging ships, and invisible stalkers plaguing the streets. Due to the nature of the Planar Calamity, with planes merging and weaving extraspatially, elementals managed to exist in relative comfort in our plane, much to the chagrin of its inhabitants. However, as numerous and mighty as they were, the Gods were allied to us. Their individual influence was limited by the nature of the pantheons; it prevented godly tyranny, but in this hour of need, it prevented their intervention... The gods are fickle. But the situation demanded unity. For the first time in eons, they pooled their power; doing so, they exhausted themselves, but it worked. A mighty asteroid fell from the skies, its power designed for the destruction of elemental entities. Though imperfect, it did its job. The meteor fell into the center of an archipelago, the epicenter of the calamity. The impact shattered mountains, wrought tsunamis, and boiled lakes. However, those who managed to avoid the collapse of buildings and the like were unaffected. Life that was common to the material plane was untouched. Trees, grass, animals, dwarves, drow, and all things with the gift of life saw the world shake around them, scared and confused, but fine. Elementals, however, were vaporized; even those buried miles underground were cooked, those in the depths of the ocean were boiled, and those in the streets were torn apart by the impact and its shockwaves. From each of the portals, once the means of invasion, the fury of an entire pantheon of gods bolted through and boiled swathes of each plane. In the days thereafter, the portals closed again, and the planes no longer overlapped. The world was devastated. Scars of the war potmarked the continents, and the archipelago's smaller islands were forced miles from the center of impact. Debris rained from the skies, settling in the oceans and pulled through the currents. The archipelago grew into a series of small islands, then small countries. An imperfect smattering, but it nonetheless contained one feature: a radius of ocean, hundreds of miles wide, surrounding a meteor that had yet to sink to the depths of the ocean. Thousands of years pass; in the present day, the meteor remains. It is known as the June Star, and rests upon mighty obsidian and basalt pillars, wrought from the bowels of the earth over hundreds of years. It is a site of holiness and secrecy. It is populated by reclusive Celestials, having claimed it as theirs for their familial proximity to gods. A fog conceals it, and travelers avoid it lest they are veered off-course.
Purpose / Function
This meteor exterminated the invading Elementals and did collateral damage to the planes they came from, unleashing its power through doorway-sized portals.
Sorcerers and clerics united to construct pillars of igneous stone. Several miles tall, they managed to stabilize the meteor and prevent it from sinking further.
Natural tunnels throughout the rock have been widened. It should be noted that June Star is the size of Delaware, and were it not for the intervention of the gods, the planet would still be boiling.