I've heard that the city in RuneScape will be for high-levelled players only. But I can't find the exact requirements needed to enter the city. What are they?
To enter Prifddinas(Elf City), there is only the quest requirement of finishing Plague's End. Plague's End does have requirements in order to start it.
- Making History - The Restless Ghost - Priest in Peril - Catapult Construction - Within the Light - Mourning's Ends Part II - Mourning's Ends Part I - Big Chompy Bird Hunting - Sheep Herder - Roving Elves - Waterfall Quest - Regicide - Underground Pass - Biohazard - Plague City
The level requirements for Plague's End are:
75 Construction 75 Dungeoneering 75 Agility 75 Crafting 75 Herblore 75 Mining 75 Prayer 75 Summoning
Once you have finished Plague's End you will have access to Prifddinas! Just head to the gates in Tirannwn, and enjoy the beautiful city.
You need to complete Plague's end quest, which requires Within the light quest, Making history quest, Catapult construction quest and level 75 in 8 skills.
EDIT: The skills are construction, agility, crafting, herblore, mining, prayer and summoning
You need to have these 10 skills up to level 75 :
Plus the masses of quests that were already mentionned. It may say different on the WIKI page but in Runescape if you check the Quest Journal for Plagues end it tells you, you need ranged and woodcutting as well.