Proposed Canon
The Situation Room, also known as a War Room and a Battle Room is essentially the primary command center for a side's armies. It is typically used by the Ruler and their Chief Warlord (if the Warlord isn't deployed in the field) for keeping track of a battle using figurines representing their own troops and the known positions of enemy forces like a table-top strategy game. When a ruler doesn't have a Thinkamancer, it is typically here that they issue orders via Natural Thinkamancy to the field.
The situation room is typically located within the Tower section of the Garrison in a side's capital, though if the capital has a palace it's may be located in there. A war room is not necessarily a specific room of its own. It is common for an office to be used for the purpose.
 Gobwin Knob
It is located in the Tower of Efdup. In the original city of Gobwin Knob, it held the Eyemancy table until the casters were separated and is the setting for much of the dialogue and strategy portions of the Gobwin Knob side of the first book. Its original design was a mostly empty, large plain stone dome with etchings of the Titans on the ceiling.Erf-b1-p045-p4
Gobwin Knob's original Garrison Tower was destroyedErf-b1-p132 and rebuilt. The new design is a large square room featuring lavish red carpet, a strategy table built something like a snooker table, stone columns decorated with coiled Dwagons and wooden furniture, all of which is heavily inlaid with gold.Erf-b2-p1-p5
Transylvito's situation room is set up similar to their throne room with a raised bench for the King and his Thinkamancer.book-2-–-text-updates-003 The positions of the figures on the table are moved by Dolls directed by the Thinkamancer.