The lab is the generic testing ground world on Adocia, mostly home to redstone, but it does feature some dedicated boxes there for building construction, notibly an area for builds for Jekyll city.
The lab consists of 256 boxes, each 16 chunks in size, however for some larger builds, such as the redstone adder just visible in the bottom left corner of the pictures (left) several boxes are combined together for more space.
It's always daytime in the The Lab, and there are no weather effects for optimum building conditions. Redstoners are encouraged to build as big as needed first to get the concept down, then compact is later.
There was a project to label each box with grid co-ordinates, but copying hundreds of chunks in one row down the one below it ended up crashing the server a few too many times, so the project was halted. The project will probably resume at some point in future, but be contiued in MC Edit, rather than in-game.
A large majority of work built inside The Lab is built by it's founder, TheSneezingPanda.