Tower of Vane

The tower of Vane is a spectacular sight, rising from the Grey Mountains far above Ubersreik; it can be seen for many miles around. It appears almost as a needle, tall and virtually featureless, formed from the stark rocky landscape, and crowned by a glass dome. The place is a centre of Celestial divination away from the confusing signs of Altdorf, a lofty peak where the Celestial Wizards can survey the portents in splendid isolation, surrounded in the dominant wind of Azyr.

The tower is situated off the beaten track and receives hardly any visitors except for Celestial Wizards from all across the Old World and their retinues. It is difficult to reach and situated in an area infamous for goblin raiding parties. Needles to say, getting assigned a place at the tower is an exciting, but dangerous, prospect for a budding Celestial Wizard.

Because of the nature of prediction, the relative difficulty of long range forecasts and the suddenness with which the portents can change, the Celestial College makes sure a variety of delivery methods are available to bring any important news back to Altdorf as quickly as possible, from messengers and trained birds to magic spells. The messengers are led by an Acolyte of the Celestial College to make sure any missive is properly respected.

Source
pg. 11
 * Warhammer Fantasy RPG 3rd ED -- Winds of Magic