There was a PC Java server I used to be a part of in 2016ish. I remember that it had Skyblock, PvP, and Prisons (I specifically remember that the Prisons was set underground) at least. They also had their own website where you could earn op tools from taking surveys(?) over and over. I could go to their website multiple times in a row and get boat loads of enchanted diamond armor and tools every day. I don't really remember much more, but if this rings a bell please let me know. I'd like to see if it's still active!