Based on the photos, you can tell this is based around the Battle Dome in Sakaar from Thor: Ragnarok where the Contest Of Champions is held. Well, it is also held on the server!

When we reach 15 total willing participants, a hunger games style contest will be held to determine a champion to whom is the last one standing. The best part is anyone can participate, so special character is needed to be tough or anything! So come on Marvel MC today to experience this epic event and explore the map for yourself!

Credit: 3d20