In this guide you can find a detailed description of this modification. What is also important is that Bruma is connected directly with the world of The Elder Scrolls V: Skyrim - this means that you only need to install the mod, pass a border and go to the new city. The add-on also has its own soundtrack as well as armors and weapons from the province of Cyrodiil that weren't available until now.
The modification contains one big city - Bruma, as well as many new quests to complete. Fus Ro Dah! Beyond Skyrim: Bruma is a rich-in-content add-on that allows you to visit a province of Tamriel, known from The Elder Scrolls IV: Oblivion.