For the most part ZOS has designed major cities in Tamriel appropriates to the Medieval standard we know concerning city defense. High walls, towers, gates and portcullises. That, though wasn't the game in Elsweyr, specifically the Rimmen gates, or lack thereof. The main entrance to Rimmen is a wide open space with no doors or portcullis to speak of. No practical way of sealing in the event of an attack or siege, which pretty much explains why Euraxia has such an easy time seizing the city.
My idea aims to fix that with an in world, immersive answer. Everything can be solved with the proper application, of Magicka.
My take, the Magical Gates of Rimmen.
The Gate has two large Braziers on each side, and we know Braziers are used in MANY Arcane rituals and Spell casting. I aim to appropriate these as focuses to channel a Barrier between the walls edges, effectively "Sealing the Gates" whenever dictated by Rimmen's Battlemages. I chose the color due to the Khajiit's use of Magicka derived from adherence to S'rendarr, or Stendarr. Wards of Stendarr have been used before, most notably in the main story questline.
CP1,500+ Master Explorer - AvA August Palatine - Console Peasant