These are the cages used to hose Evangelions before launching them to combat Angels. The Entry Plug is inserted into the Evangelions in the cages, and the launching rails send the Evangelions vertically upwards to Tokyo-3. There are multiple Evangelion cages and most appear to be near Central Dogma as seen in Episode 19.
This article bears the unpleasant designation of "Stub." This is a Bad Thing. Provide a great service to NGE fan-geeks everywhere by making it awesomer!