Lost Ark Codex[lostarkcodex.com] is one of the oldest websites dedicated to the game Lost Ark. Do you want to know how to get a certain item or what to do with all the different coins, what are they good for. You can find the answers on the Lost Ark Codex website. Every item, every quest is listed there. Probably not everything will be available in the EU/NA version right away, but this should be your first place to go if you want to know something about certain items, quests etc.

On the Lostark-ES[lostark-es.com] website you can find an interactive map of Lost Ark. There are all the finds of certain items listed and also monsters, hidden quests, etc. for the adventure book for example. Dungeons are also available!

Lost Ark Tree[lostarktree.ru] is a skill builder website. There you can create your builds or view them from other users. Additionally you can sort by ratings, PVP, PVE, date etc. The Website is also available on english.

Papunika
Papunika [papunika.com]has some really good info, especially on boss mechanics.
Thx to jeffswilkinson

Event Planner
Event Times in Lost Ark[lostarkplanner.web.app]
Thx to Glaiverity

Sry but Steam is blocking Google Docs links, so i must remove them.