WinterMC is a modded survival SMP that just started with a brand new world so everyone is jumping in at the same time. It is meant to be chill and relaxed but there is still tons to do.
The modpack is big with over 120 mods and it leans into exploring and building. The world gen is custom and it makes big landscapes with continents and islands so it feels huge when you travel.
I noticed it has a live web map so you can look around and find bases. Builds are protected with chunk claiming so you can build without worrying about griefing. There is also an economy and server wide ranking systems.
If you like adventure there are lots of extra structures like better dungeons strongholds and mineshafts plus more mobs and mythical creatures. If you like tech you can do Create machines with trains or go for higher tech automation. There is also better food and fishing and lots of storage and building mods so bases can look really nice.

