From the RuneScape Wiki, the wiki for all things RuneScape
The location of the Astral Altar.
The Astral altar is used to make astral runes using the Runecrafting skill, and also used to pray at and change to the Lunar spellbook from any other spellbook or back to the normal spellbook.
With an astral teleport tablet from the runecrafting guild, a player can change back to the normal magic spell book from ancients by praying at the altar twice to activate lunar spells then deactivate leaving the normal spell book.
It is unique among Runecrafting altars in that it does not have ruins which must be accessed with a talisman, and unique among praying altars in that it does not recharge prayer points. The praying altar at the end of Desert Treasure is used to switch to Ancient Magicks, however, drains prayer completely.
It is located on Lunar Isle, south-east of the village. To go to Lunar Isle players must have completed the Lunar Diplomacy quest. Players may want to watch out for the three Suqahs that are on the path to the altar, as they are aggressive and fairly strong.
Players who wish to talk to the Oneiromancer can find her floating usually just north-west of the altar, however, if you are not carrying a seal of passage when you try to talk to the Oneiromancer she will tell you that you are not welcome on the island and teleport you to Rellekka.
- The astral altar and the Ourania Runecrafting Altar are the only two altars that do not require a talisman, tiara, or Talisman-staff to enter, because these are the only ones that were not destroyed by the Fremmeniks.
- Many players who wish to switch from ancients magic to normal will use this altar because it does not drain your prayer and it is easy to access with a lyre and seal of passage.