We call it the Hum.
  In its entirety it is, of course, only a rumor. A mere tale. But strangely, across all of the stories you may hear about it, they are practically the same. Those who have heard the story recognize the signs and, when in that situation, escape as soon as possible, afraid of what the truth may be. However, in my travels, once in a blue moon, I will come across someone else. Someone who was overpowered by the incredibly human trait of curiosity who, once hearing the Hum, sought out its source. And in the few stories I've heard, its the same:
  Ruins that are long abandoned, unnatural in how they are still able to stand. If you dare to go in deep enough, enchanted by the droning Hum, deep within you will find a frame of obsidian towering over you, seeming untouched since the beginning of time. Destruction surrounding it. And in the back of your mind, it is said that you know where the destruction came from.
Within the obsidian frame is a sheet of violet, comparable to stained glass in nearly all regards except for the unnerving infinite swirls and the shimmering effect that escapes the smooth black rock that encases it. From this point, a choice has presented itself to you; turn your back on it and live trying to forget, or fail to overcome the curiosity.
  Perhaps, to you, it may seem that I know these details all too well, despite previously mentioning how rare it is to hear a story similar to this. I know the reason for this. And you should too.
  I have also heard the Hum. And curiosity won.

I was traveling farther than I ever had, personally exploring and mapping the area and the occasionally towns and villages I had come across, and made the foolish decision to depart from a town right before nightfall. I was too far away when the sun began to creep behind the horizon.
  That's when I heard it.
  Subtle at first. It could have been easily mistaken for a howling wind, except for two important details I couldn't ignore:
  The hair on the back of my neck stood straight up, and, jarringly, the sound of all of the animals of the forest had ceased.
  As thunderclouds rolled in and hid the moon, and a distant rattle of a skeleton's bones jerked me out of my trance, I felt as if I had no choice but to seek shelter, no matter how dangerous the shelter could end up being.
  I sought out the Hum.
  It was easier than I thought it was going to be. Rather than trying to listen to its origin, it seemed my mind was attracted to it and led me off the path I had been on, and into the surrounding forest. I hoped that whatever was leading me to the source could also lead me back to the worn trail in the morning.
  After stumbling from underneath the looming trees, I was awestruck at the sight before me.
  A crumbling stone bridge, dirtied by time, spanned over a deep valley to what appeared to be an old Keep carved into the mountainside.
  The bridge looked sturdy enough, as long as I placed my feet in the right spots, so I decided to make the journey. The buzzing sound I had been following slowly began to grow as I crept closer. I hastened due to the groaning sounds that were coming from the forest, making it known to me that I had to seek shelter immediately.
  The entrance to the Keep was an open archway. I had to push past overgrown vines in order to enter.
  Inside, you could tell that it had once been a beautiful place. Beneath the thick layer of dirt and dust that covered everything was polished stone. On the walls, old, presumably hand-weaved fabric hung to be admired. If there was anything of value, it had to have been stolen. The room was incredibly empty. There was one hallway in the far right corner, and I continued to seek the Hum.

It took me a few minutes of wandering down intersecting halls, following the roaring sound. Eventually, I found a door.
  It was old and wooden, and the hinges were rusty. I prayed that they were still able to move.
  I opened it, having to use all of my strength.
  The room was illuminated with a purple light, and it was filled with a thin layer of lavender fog. The sound bellowed in my ears. There was a breeze pulling me in. Then I saw it.
  A deep black frame. A stained glass sheet.
  The source.
  On the floor was scratch and burn marks surrounding the obsidian.
  Amazed, I stood there. Perhaps a minute, maybe an hour. It was hauntingly beautiful.
  I closed the door behind me.
  I put down all of my belongings in the corner, unconsciously making the decision to keep my small pouch tied to my belt where I kept my riches.
  Despite the feeling I had in my stomach, I tenderly touched the violet shade. Immediately, I was pulled in.
  I came crashing through.
  The flash of heat was overwhelming, apparent by my sudden sweat and the difficulty I had opening my eyes. Through squinting, I was able to see where I ended up.
  A sea of red land. A blanket of lava. Multicolored forests in the distance.
  I felt nauseous. I managed to stand up, trembling. Other than that, I was frozen, taking in the view of what I had stumbled across.
  I ripped off my cloak, wiping my face on it, and decided against my better judgement to walk towards the cerulean and crimson forests.
  The oppressive heat made me slower than I usually was. When I finally made it to the edge of these strange forests, something began to emerge, rushing me. A choking sound came from my throat, but failed to form words
  It was a pig. On its hind legs. Wielding a golden sword.
  I barely got my dagger unsheathed before it had swung. I dodged his first attack and parried his second. As I continued to step back, I tripped.
  His sword was sharp, poorly cleaned. Dried liquid the color of rust was crusted onto it.
  Not knowing what else to do, I shoved my hand into the pouch I still carried, grabbed a handful, and threw it at him. I hit the hard ground and shielded my face from my doom.
  When I noticed I was still alive, I peeked. The view of my gold coins and nuggets caused him to throw his sword away. He was on the ground also, making sure to grab every single piece he saw.
  In a moment of brilliance, I got up and ran.
  I was nearly back to the portal when I heard a shrieking sound. I chanced a look.
  Flying through the sky was something reminiscent of both a ghost and a squid.
  The thing looked at me, and, without hesitation, began to attack. I narrowly missed its fireball, but that didn't stop my hair from singeing as it passed by.
  The portal was within view.
  I ran faster than I ever had, somehow still being cautious with my footwork.
  I dived back to where I came from.

My head slammed against the floor. I was upside down against the heavy wooden door. My heavy breathing drowned out the Hum.
  Suddenly, I wondered if the reason why you rarely hear about such a thing was because most, or any, never made it back.
  Perhaps some thing would have been better left unknown.
  I decided I would settle in the front room for the night.