Lunar Isle is an island shaped like a crescent moon, located in northwest Gielinor. It is accessible for members who have gone far enough into Lunar Diplomacy. The Astral altar is located on this island. There is also a bank, a magic shop, a clothes shop and a little island to the east inhabited by Suqah. It is home of the Moon Clan, beings with magic coursing through their blood, who are bitterly at war with the Fremennik.
A Seal of passage is required to interact with any of the NPCs on the island. If the player interacts with an NPC, there will be a few chat interfaces, followed by being kicked off the island. Players can choose not to continue on the chat interfaces to avoid being kicked off the island. After completing Dream Mentor, players can use only the bank booth where 'Birds-Eye' Jack works without a seal of passage, if they happened to forget it. All the other NPCs require the seal of passage, still.
After completing the elite tier of the Fremennik Diary, players will no longer need a seal of passage to interact with any native Lunar Isle inhabitants.
- Moon Clan Fine Clothes - It sells Moonclan robes which can be stored in your player-owned house.
- Astral altar - Here, you can switch your spell book to Lunar spells, or switch back to the standard spells if you are currently using Lunar spells. You can also make astral runes here with the Runecraft skill and purchase Lunar equipment from the Oneiromancer.
- Lunar Isle mine - The mine contains rune essence rocks in the centre, 6 gold in the west, 3 silver south, 3 gems southeast, and to the northeast 1 gold, 2 silver, and 1 gem rock, like the ones in Shilo Village.
- Flax - There are flax fields outside the main gates.
- Brazier - Here you can access the Dream World during Lunar Diplomacy, Dream Mentor, and Dragon Slayer II.
- General store - This is just a normal general store which sells the usual things.
- Suqah - These creatures are combat level 111 Slayer targets. They use magic and melee attacks, and are great for training combat. There are a total of 25 on the Isle (This is used for a clue scroll step).