Shadow Sanctum

Hidden betwixt the tears in the fabric of light is this place, a sanctuary for those who watch Equestria secretly from the shadows. As vague shapes coalesce into solid matter, several things are evident: hard stone, pried from volcanic layers and chiseled into fine bricks; plush, patterned carpets imported from unpronounceable lands; lamps crafted before the current generation was even a furtive dream of the visionaries of old. The room itself is circular, with a stone platform in the centre upon which is a large round table, dark in hue, the unnatural sheen of its surface concealing depths of memory. The ceiling is dome shaped, with an opening in the middle which leads, quite intriguingly, into a nebulous void. In the still silence of the in-between the whispers of the past can be heard, however dimly.

Four doors lead out into other chambers. The north door is of birch, and on it the symbol of an ancient pedestal, black tendrils seeping out of the cracks upon its surface. To the west is a portal of cedar, and on the front is the symbol of a leaf dripping a dew drop, except that, instead of glistening in the light, the dew drop reflects darkness. Southward the way is barred by oak, a sigil depicting an open book etched into it, which seems ordinary enough until one realizes that the book's shadow is busy editing the words on the pages. Going east one finds a door of mahogany and a picture of a black vase on a white background. Or is that two white ponies on a black background?

There appear to be a number of alcoves between these doors, though so far all of them are concealed by heavy curtains except the northeast one. This alcove is striking because of the presence of a tall, white obelisk of what appears to be pure limestone. If one looks at the surface carefully, one might catch a glimpse of the Royal Palace.

Directions: 

Only Shadowwalkers can access the Shadow Sanctum, though if you're clever enough you could just sneak into a still-open portal somehow