Dark Souls Remastered is, as you might guess, an updated version of the 2011 action-RPG, with support for 4K resolutions running at 60 fps. But if that's not quite enough of a visual upgrade for you, the "Evie's Ultra HD Dark Souls Remastered Retex" mod that recently appeared on Nexus Mods might be worth looking at.
Based on the Firelink Shrine UE4 Remake that was released in March by the same creator, the mod is a work-in-progress redo of all visible textures in Dark Souls Remastered. It covers "NMaps, Height Maps and Albedo Textures for all textures within viewing distance," in native 4K and without upscaling. It is not, however, a point-for-point recreation of the original: "This retex is not [meant to] be accurate to the original game, it's created to my tastes," the mod author noted.
It's not complete but it is well on the way, and the comparison screens on the mod page look really good. Regular updates are promised, and as befits a proper mod, the installation process is a little convoluted: You'll need to grab the DSR Texture Packer and Unpacker, after which you'll download part 1, 2, and 3 of the mod and install them in order. If you'd like to remove nudity, because apparently there is some, there's also an optional "SFW" add-on.