Druids could have massive gatherings once at a time. To talk about things they've noticed, possible world/nature threats, welcome or test new druids, or other things.
I'm looking for ideas and details about this druid gathering thing. Could you post any suggestions? Why would druids meets up? How do they tell each other about where/when to meet? What are they doing when they meet? Do they do it often or rarelly?
I have some ideas but I'm very interested to read your thoughts too and get some inspiration.