This is a modded SMP called The Asylum SMP and it is on season 3 right now. It uses the Better Minecraft 4 modpack so there are quests and new bosses and mobs and even new dimensions and more stuff to do.
The server is for players who want to join pretty often and hang out with a small group. The community feels close and relaxed and people are there to have fun together not just rush through everything.
The Asylum SMP is strictly 18 plus. Voice chat is required to be on the server but you do not always have to talk if you do not want to. They also run a monthly games night on their Discord where the mods host different games with everyone.
If you want to join you have to apply to get whitelisted. If you have questions you can ask the staff or message the owner and they will help you out.
