Modder theblackfist has released a pretty cool mod for Skyrim special edition… Assault on Valenwood, add a new mission and allow you to explore the entire province of Valenwood.
In this modification, players will partner with the Imperial Legion as they travel through Valenwood and reclaim a province, city by city. The local towns of Bosmer and Khajiit will also join your cause.
Note that this mod requires Skyrim SE version 1.5.73 and later, as well as all of its DLC.
Now, as its name suggests, players will be able to explore the entire province of Valenwood. The modification includes a new world map for Valenwood. Valenwood is a beautiful landscape with stunning design work and creative innovation.
You can download the modification here. To get started, you have to go to the Solitude docks and board a ship called The Avenger. Then you have to find the hatch at the end of the ship and open it.