So I figured I'd post this as a casual map, because I really don't see it as a horribly competitive thing.

http://www.bungie.net/Forums/posts.aspx?postID=24469355
(click t3h picture)

Super lame backstory!:
Back when the Human-Covenant War first started, the humans managed to get their hands onto some of the Covenant's treasured and well-used teleport-nodes. Granted, the originals were severely damaged and well beyond the capabilities of most engineers to repair in any feasible amount of time, so they were brought back to earth and stored in a warehouse.

But eventually the war began to escallate, and things weren't looking too good for the humans. A crack team of eight scientists was assembled to analyze the technology, see if they couldn't get it working again, and glean what technical knowledge from it that they could. At first, things began to move slowly. The scientists had never seen technology this abstract and powerful before, and so didn't know what they were doing. That is, until one day, one of them had a breakthrough, figuring out how he thought the device worked.

The very next morning, he and two of the others began tinkering with it in ways that should never have happened. It began to draw its energy from the earth itself as the power available through the warehouse proved insufficient to fuel its point-singularity generation. Before long, the earth began to tremble, and the floor-plating and cement beneath the warehouse grew warm and soft, giving way easily to the molten rock that rose violently towards that which needed its power. All three scientists working in proximity to the device were killed, along with all but two of the rest (who escaped severely burned and emotionally and mentally scarred).

As the new geothermal vent continued to pour out its energy, the node began warping and twisting the facility to be sufficient to its own design, spawning three more receiver nodes in addition to the first. But then the power went out, as the earth stopped fueling the teleporter's circuitry. All too soon the Humans assigned engineers and yet more scientists to rebuild the facility into "something useful."

Pipework first had to be laid beneath the floor of the structure capable of supplying the teleporter with enough geothermal energy (read: lava) to activate and send to the other nodes, and then a structure built capable of relaying that energy into the teleporter in a relatively harmless manner, and the receiver nodes needed to be removed from the sender as far as possible to prevent the possibility of point-singularity collision (read: really big boom). The result was this.

As the war drew to a close, the facility continued to be remodeled. Eight pillars were erected around the central structure in memorial to the scientists who had died there, but that wasn't the end. The Spartan program, after John 117's success in retrieving Cortana, was continued on earth with this facility as one of its favorite training rooms.

The result was Pyroclast.

Technical Side:
So the map features a few things new to my forging repertoire: namely weapon placement theory, geomerging, and extensive interlocking. There isn't much to the aesthetic side of it, as I tend to focus more in my forging on gameplay and how it works over how it looks. Every static item on the map (excepting the back wall) is either interlocked or geomerged somehow, which is a first for me (didn't realize until posting this, either).

Generally the map will support with plenty of elbow room a full party of 16 players, but to cut down on lag, I recommend no more than 10 or 12. It's also fun for small teams as well.

In terms of the weapons, I'll edit this post with a more complete list later, but the map does come well-equipped with the following:

4 machine gun turrets (meant to be ripped off and not-respawnable)
4 carbines with no extra clips
4 beam rifles with high respawn time
4 BRs with no clips
4 trip mines
4 grav lifts (supposed to be used only to get the power weapons, but can help maneuver the map if used cleverly)
1 of each of the other useful deployables (bubble shield, deployable cover, regen, energy drain)
4 assault rifles
2 SMGs
2 needlers w/no clips
2 brute shots w/no clips
1 shotgun (no extra clips and a long respawn time)
1 sword
1 hammer
2 maulers (no extra clips)
8 frag grenades
8 plasma grenades
2 plasma rifles
2 brute spikers
2 magnums
2 plasma pistols.

The Map Itself:
First some screenshots so you can see what I'm talking about:

Pyroclast consists of one main plus-shaped structure with four multi-levelled paths to the top. The most heavy function of interlocking and geomerging I'd yet done, the path up goes from the stairs (third picture), to the walkway under the slant-bridge (best seen second picture), to the slanted bridge (first picture - they're backwards <_<). In the center, as you can well see, is the exploding fiery furnace of death that everyone trying to hold the hill there loves to hate.

This structure is surrounded by eight pillars, with interlocked fence boxes atop them. From four of these, an interlocked open double box goes to one side, holding spawn points and the means to get the power weapons which rest atop them. They create courtyards of sorts between the ones with interlocked open boxes and the 'volcano' structure, which tend to be good places for showdowns. The brute shots, needlers, and close-range-killers are atop these platforms, and are only accessible by grav lift (or if you're a really good jumper - read on).

In the corners of the room are two levels of raised platforms intended for sniping. The lower level offers limited visibility and serves as little more than a housing for the BRs and some spawn points. The upper level, however, contains teleporter receiver nodes that can only be reached by jumping through the flames to the sender node there (it's random which one you go to). In these sniping rooms are beam rifles with long respawn times. Each one is plainly visible to all of the others, and each one only views about 1/2 to 2/3 of the field in play.

There is also a sort of outer-ring to the map that I hadn't intended but actually works out quite well. Formed outside the eight pillars and anchored by the BR rooms, many shoot-outs happen therein.

Special Gametypes:
In the Cloud - KotH
There is a single hill in the midst of the fiery explosions, and it is your job to individually hold it uncontontestedly. Game plays to fifty, and when you're in the hill you can't move, can't shoot, and can't hit. You have a 2x overshield and double damage resistance, but if someone shoots the fusion coils around you, you're screwed. It's hard to get in the hill, too, especially with the teleporter right there eager to send you off to one of the sniper platforms. The game plays well, albeit slightly annoyingly from what I've heard. Maybe someone can help me perfect it?

Vented - Assault
This one's a bit more complicated. The defenders spawn in the bunkers under the 'volcano' structure, while the attackers outside it for the first round. It is the job of the attackers to retrieve the bomb from one of four spawn points atop the pillars and carry it slowly to the center without dying. It is a difficult task, and as of yet I haven't quite figured out how to make the bomb disarm time go any better. I would hardly call it a complete gametype, but I am eager to post this map, and this a game that should go with it. It hasn't been tested much, but if someone wanted to give it a few tweaks for enhanced gameplay, that would be cool.

Non-special gametypes supported:

Slayer (most variants, though spawns might be strange with Team Slayer)
One Flag CTF
Multi-Flag CTF
Neutral CTF
Juggernaut
Infection

Tips & Tricks:
So the close-range killers all spawn on top of the pillars that don't have prespawned grav lifts attached to them. Unless you're really good (and I mean really good) at jumping out of the sniping platforms, you'll need to find another way to get there. Here's how:

1. Pick up a grav lift. "Oh there it is!"

2. Deploy grav lift in right location. (image is kinda pink, I know)

3. Retrieve your tool of death. "I can haz hammer-burger?"

4. Go kill things. "He never saw it coming..."

There is also a technique to be known for jumping through the portal at the center. Even master jumpers can be caught in the constant explosions, and the most experienced can be put to shame. It's all about timing:

Fig.1a A correctly-timed jump:

Fig.1b The result of a correctly-timed jump:

Fig.2a A poorly-timed jump:

Fig.2b The result of a poorly-timed jump:

More Action Shots:

And of course, the obligatory wtf moment:

That's all I've got.

Download Pyroclast
Download "In The Cloud" Variant
Download "Vented" Variant

Feedback is wonderful: please, if you should download, tell me what you think.