Open Cities Skyrim is a comprehensive project that aims to bring back at least part of the feel of Morrowind - specifically how most of the cities were a natural part of the world and you could just walk in without loading screens. The added immersion and realism goes a long way, probably a lot more than you might think. Ever wanted to ride your horse into the center of Riften? Well now you can. Need to get some help from the city guards to vanquish a foe? Run toward the gates and the guards will do their duty while you can seek safety within the walls. The town guards make for some very interesting interactions this way. This will also make running dragon battles that much more interesting since the flow of the battle won't be interrupted by the loading screen and all of the city guards can be involved at the same time.
Patches In The Patch Archive
CL Cities - Whiterun: Adjusts navmesh data and makes copies of objects from CL Whiterun into the open worldspace.
Skyrim Sewers 4: Provides access to the sewer areas from the open city spaces.
Drinking Fountains of Skyrim: Copies the drinking fountain objects into the open city spaces. Patch written by Hanaisse.