A sleek arena to use with the any spleef plugin.
The arena is fully customizable. It includes a lobby with a view on the arena and spectator area with freedom of movement. There is enough space to build an over arena hub for spectators.
The terrain is not too difficult and not too big just the right size to have fun knocking opponents off.

It is free to use on your server. Though it does figure in my own.
You can test it out on the server: 174.138.171.122:60036
Yes I'm advertising ;)

It's a remake of my PVP arena. It's a suggested way to moidify it. Link to the project here: http://www.planetminecraft.com/project/mob-arena-2158054/

Additional Notes

Can easily be changed to accommodate PVP or Mob Arena.

Schematic: The schematic loads on the North-West side. The structure will then generate on South-East side of that corner.

-Note there are three obsidian blocks on the North-West side. The top one just limit's the height. The lowest limit's the ground level. The middle one limit's the recommended level to generate schematic (where the schematic should load flush to the ground). You may see how it should look like on the last picture of the gallery.