The Lighthouse is a members only area just North of the Barbarian Outpost, and plays a big part in the Horror from the Deep quest, in fact, it's the only thing in RuneScape it's featured in. The Lighthouse can only be entered during and after the quest, the island can be visited prior to starting however, it's also a very good place to train combat stats on the dagannoths within the caves underneath.
How to get there
The most common and fastest way of getting to the Lighthouse is by using a Games Necklace teleport to the the Barbarian Outpost, running North to the stepping stones, crossing those, head North a few more steps, then you're at the Lighthouse. You can fall off of the stepping stones however and deal up to 40 damage.
This lovely lady is an NPC in which you talk to in order to start the Quest Horror from the Deep. She can be found right at the entrance door to the lighthouse. There are no requirements to talk to her, just get to the Lighthouse.
This handsome fellow here is Jossik. You save his behind from being torn apart by the dagannoths in the Horror from the Deep Quest. Once you have completed the quest, you can go to the second floor to talk with him and obtain one of three god books from him. In order to claim another, you must complete all pages of the one you have currently. If you lose you book dying, dropping, etc. You can talk to him to retrieve it.
Inside the lighthouse
Down the iron ladder is where you'll find the gate which leads to the cave in which the dagannoths inhabit.
Guide Made by: Joe
Corrections submitted by: Jack