This is a pretty big stupid update I worked far, far too long on. Tons of changes.
Some of the really big ones:
3d skybox
New underground area complete with a funny lake of non-water substance, a bridge over said lake, and a vertical shantytown with a functioning crane
Dev rooms for if you're building and don't want to be bothered (might add locks to them soon)
More dumb secrets, plus reworking some of the existing ones

Enjoy!

Improved the catapults substantially by making them 7 func_doors glued together. Besides probably being bad mapping practice, this makes the launch acceleration a lot smoother and props don't clip through nearly as often.

There's also some less-than-breakable castle walls with breakable barricades on top of the main hill for you to smash with the catapult, and some funny secrets.

Next update should be an actual skybox and the funny caves.

Massive overhaul of the valley. It's about 2.5 times bigger and now has two (2) valleys instead of one. The bunker with the funny statue on it now has blast shields, and the giant bunkers have huge catapults for flinging: players, corpses of players, props, bombs, cars, mechs, anything you can fit on them really.

Things to look forward to in the next update, whenever it comes out:
Massive underground caves area with even more unreasonable displacement geometry
3d skybox and more detail in the valley so it's more flavorful
Loads of secrets, potentially including a spooky bonus room

Expanded each bunker's underground area to include a gigantic elevator for truly unreasonable contraptions, as well as a small player-sized elevator running between the large cargo lifts. No secrets this update.

Next update will include trustworthy source engine siege weaponry for each bunker, a huge underground cave complex, more secrets, and making the valley itself even bigger.

Initial addon creation.