Step #119 in the Expanded Vanilla list
Similar to Illuminated Palace of Vivec it adds a bunch of candles near said Palace. Except that this version of the mod greatly reduces stress on your PC by merging the hundreds of candles together into just 3 meshes and only 6 light sources.
The base texture is also hooked up to vanilla textures so any texture replacers you choose will seamlessly fit in.
Vivec Palace Illuminated - REDUX.ESP