OFFLINE

Here's a list of buildings either existing or planned that can be built:

Tower (Navigational or Combat)
Fortification (Castle, fort, etc.)
Habitat (for living, storing items, recreation etc.)
Port (to store boats and ships)
Ship (stationary ships made out of wood, used as a variaty to regular houses/fortifications, possible to move with plugins in future)
Farms (wheat, cactus, sugar cane, obsidian, etc)
Snow/Sand based buildings (as a variaty)
Arena (for PvP battles which I'm planning to build)
Wall (to seperate a land)
Bridge (to connect two lands over river or height)
University (housing advanced equipments under different faculties, such as potion brewing and enchantment table)
Brewery (creating potions)
Library (enchanting weapons)
Mine (for storing mining equipment for a nearby mining site)
Lumber Yard (for storing woodcutting equipment for nearby forests)
Light House (advanced version of navigation tower, housing pistons and rotating light)
Church (aethetic reasons and worshiping Mojang employees)
Barn (for housing animals)
Market Place (for possible shop plugins, or just a gathering centre)
Transit Tunnel (for traveling with minecarts and powered rails)
Canal (for traveling inbetween continents by boat)

Ship Naming Convention:

Ships are named with a prefix in front. For example, a British ship named "Victoria" would be called HMS Victoria, with "HMS" standing for "Her/His Magesty's Ship". Each person would use a prefix for their own ship.

Current classification of some existing building types:

Tower:
    Navigation Tower: Built with height as a priority, and many torch or light source to show location both in day and night.
    Combat: Built with size and safety as a priority, for either escaping monsters at night, or from where monsters can be engaged at.

Fortification:
    Bastion: Anything small built out of stone or wood with the aim of defence. These are rather small.
    Fort: A sizable keep or a series of small towers connected together to provide defence.
    Castle: A relatively large keep enclosed with walls around.
    Fortress: Anything bigger than a castle. May have multiple rings of walls, traps, sections built out of obsidian, and other buildings inside.

Habitat:
    House: A small house or storage room.
    Manor/Estate: A large house with multiple floors and rooms, as well as objects around.
    Village: 2-9 small houses nearby together.
    Town: 10 or more buildings together, as well as land nearby. May be walled.
    City: Bigger than a town, with a large number of buildings, usually walled. Optional to include a citadel, which is a stronghold somewhere connected to the city, to protect the nearby land.

Ships (None-combat):
    Cog: Extremely old 10th century design, a single masted and square rigged small design. Very small.
    Sloop: A single masted and decked ship. Small ship.
    Caravel: A 15th century single deck explorer ship, with a bridge, two masts, designed to be fast and light. Medium sized ship.
    Clipper: A fast and thin ship with 3 masts and a single deck. Large ship.
    Carrack: A large old 15th century ship intended for ocean-going trips, 2-3 decks, a bridge, and a few guns for protection. Very large ship.

Ships (Combat):
    Brig: Small single deck boat with 10-18 guns, two masts. (small ship)
    Sloop-of-war: A small, light and quick single deck ship with up to 18 guns, and three masts. (medium-small)
    Frigate: A fast warship with 1-2 decks, (armed only on one deck) of up to 28 guns, and 3 masts. (medium sized ship)
    4th rate Ship of the Line: A medium warship with 50-60 guns, 2 decks and 3 masts. (medium-large ship)
    3rd rate Ship of the Line: A medium-heavy warship with about 74 guns, 2-3 decks, and 3 masts. (large ship)
    2nd rate Ship of the Line: A heavy warship with about 86 guns, 3 decks, and 3 masts. (very large ship)
    1st rate Ship of the Line: A super heavy battleship with 106 guns or more, 4 decks, and 3 masts. (huge, gigantic ship)

OFFLINE

Has the Arena been built yet?
If not can i build it? =D
Whats the material ganna be?
Also why cant we have a smaller land Dx
This thing is too huge its making traveling difficult ;w;

OFFLINE

The arena will probably be built in or around the city, but much in the future as PvP is not really practical right now. As for travelling, the Nether exists for a reason.