Jimmy's Lab is fully filled with handy inventions and known to have a screen to see the outside of his door. Jimmy's lab is in almost every episode and that's where he built Goddard. He has plentiful pieces in there to make inventions like wires, batteries, canisters, engines, oil, electricity, lasers, motors, and other stuff. It's located in the backyard behind Jimmy Neutron's House in Retroville located in Texas, in the United States of America with Alaska and Hawaii, in North America, on Planet Earth.
Jimmy's home away from home, located underneath the clubhouse on the Neutron property. There are several ways to get in, primarily through the use of a DNA scanner that is attached to the clubhouse. Through the use of a single hair strand from Jimmy's head, the scanner will analyze it and allow the person inside. This has been shown on many occasions. A notable example is Carl having a bag of Jimmy's hair to allow himself and Sheen inside, another is when King Goobot stole a stand of Jimmy's hair and used it to gain entrance. It is known that the clubhouse also has defenses against those without Jimmy's hair such as when Jimmy and Cindy were switched into each other's bodies, the scanner rejected Cindy's hair shouting "Girl Hair!" and Neutron who was currently in the former's body was kicked away from it.
Another route into the lab is through the use of an express tunnel located within Jimmy's room hidden beneath a poster. Although it is not used much due to the bugs not having been worked out during its use, it provides an extremely quick entrance into the lab.
Other Entrances and Exits:
There's also an entrance under the Welcome carpet in front of Jimmy's club house, which can be activated from inside.
In emergency situations (mainly when the main door is blocked) Jimmy can exit through the sour pipes which will lead him into town.
Underneath the Clubhouse
The lab itself was originally a basement before Jimmy made it a lab which was shown when he, Sheen and Carl went back in time to convince Hugh to invest with McSpanky in Time is Money. After Jimmy had became interested in science, he converted the basements into a very spacious lab that leads close to the town's sewer system which provides a quick escape if the lab were to be infiltrated. The lab is also protected by several reinforced carbon steel doors that keep all enemies out and is supposedly nearly impossible to break through; even though it should be noted that Sheen has been able to penetrate them both, first with his distressed voice after his ultralord action figure was stolen and second when he was controlled by Grandma Taters but these could have just been a gag that was featured for the show as these incidents haven't occurred since. On a whole, the lab is mostly used to help Jimmy's inventions and when he is needed to save his hometown from threats most of which are his fault to begin with.
The lab holds many of Jimmy's most impressive and dangerous experiments most of which are contained, such as the Love Potion, N-men Power Packs, Time Booth, Jimmy's Rocket, Hypno-beam and several other experiments that have either put Retroville in danger or are used to save it and more rarely to be used for personal gain by Jimmy or his friends.