Nightmare Zone

hey guys, just getting back into osrs and i've been trying to level up my combat skills (68 - 75 str, 60-75 att, 45-60 def) and ive been told nightmare zone is a good method for this! I've never heard of it before and googled it but im still pretty confused. What is it? How do I play it? and do i lose my items upon death?

Any help would be great, thanks!
(a simple guide on nightmare zone would be awesome )

It is the RS3 version of the Dominion Tower if you're familiar with that. If not, it's basically an instance where you fight against quest bosses again. You play by heading just outside the northeast entrance to Yanille (I believe there is a tutor that can walk you through the process once there). The best thing to do if I'm not mistaken is to go to like World 2 and pay people that have a good set of quests done to create an instance for you (ie: you don't want elvarg in your instance as that will greatly reduce your experience per hour as well as the time you will last per instance).