Flagstone floor, stone block walls, thick, reinforced wooden door, narrow slit windows high on wall, castle banners and colors, candles or lanterns for a light source, racks with weapons of the era: sharpened spears, poleaxe, polearm, halberd, tables holding spiked maces, flails, clubs & mauls, swords fanned out on wall displays (short, long, broad & claymore), bins of arrows, stacks of unstrung bows, bowstrings, quivers, crossbows, bolts, stands & suits of armour, chain mail, banded mail, leather undershirts, shields with a crest or coat of arms, helms, helmets, gauntlets, throwing knives, ceremonial armour, barrels of oil, explosives, cannon balls, shot, pistols, leather sheathes, oilcloth, chains to hoist heavy armour, horse plate, an adjoining crafting area where weapons and armor are maintained (granite grinding stone, anvil, sheets of steel, forge, craftsmen, apprentices, flying sparks, white granite dust on floor near sharpening wheel, red hot metal, hooks, hammers, tongs, barrels of water for quenching), soldiers
The clink of metal, hammer on steel, the hiss of steam, crackle of flame, the grinding rasp of metal against the granite sharpening wheel, chain links clinking, creaks, scrapes, the quiet crumple sound of leather creasing, heavy boots against the stone floor, grunts, steel sliding into a scabbard, stampeding footsteps as soldiers rush in, shouts, cries, slamming the flat of a blade against a shield to gather every one's attention, wooden handles/staffs shifting against each other, wooden poles grounding against the floor in a solid tock, orders being yelled out, call to arms
The tang of metal, smoke, oils, leather, cold stone, wax, gunpowder, soot, blood, polished wood, sweat
Leather-wrapped sword handle against palm, the drag of a shield and armour on shoulders and arms, the burn of chafing leather against skin, the pull of a chain mail shirt, curling fingers around a smooth pole weapon, testing the edge of a blade for sharpness with thumb or finger, the press of bodies, bumping/nudging against other soldiers, a painful burn from a careless spark at the grinding wheel, slinging a quiver over the shoulder, using pressure to bend a bow and string it, running a finger through the feather fletching, holding a bolt or arrow shaft up to check for warping or flaws, pulling on gauntlets, sliding helm over head, squinting to peer through the helm slit or swinging the visor open, tightening scabbard belt around waist, widening stance and bracing for the weight of chest plate, moving arms to make sure joints are well-oiled and there are no obstructions to movement, pulling a weapon from the wall or rack, sorting through a pile of weapons or helmets for a sharp blade or sturdy fit, sweat sliding down face, neck and back from the heat, hefting the shield on arm, taking armour pieces to the craftsmen for last minute adjustments, collecting shot into sacks
--The words you choose can convey atmosphere and mood.
Edmond raced into the armoury, following the acrid scent in the air straight to the four casks of oil sitting along the far wall. The squire rubbed at his watering eyes, debating on how to best transport them and then heaved the first into his arms. Rolling the casks across to the doorway would save his energy for the stair climb to the castle walls, but the uneven flagstones might weaken the seal on the barrel. He dare not risk it. A fire here would not only claim his life, it would write the ending to the war.
The armory walls shook, rattling the racks of polarms and filling the air with dust. The truth behind the blast chafed Lord Fadelin like ill-fitted armour--his party of soldiers had failed to sabotage their enemy's trebouchet. Another hit, maybe two, and the walls would collapse.
--Similes and metaphors create strong imagery when used sparingly.
Example 1: (Simile)
At the far end of the armoury, a dozen halberds waited in a wooden rack like soldiers eager for battle.
Example 2: (Metaphor)
As enemies hacked at the bolted armoury door, fear slipped down Amos' back in burning trails, setting fire to the raw skin beneath his chain mail shirt.