Oak Ridge National Laboratory, or ORNL for short, is a big science building where super smart scientists work together to try and make new discoveries and come up with new technologies that can help the world be a better place. Think of it like a huge playground for scientists where they get to play with really fancy and expensive toys like supercomputers and particle accelerators.
ORNL is located in a place called Oak Ridge, which is in Tennessee, USA. The building itself is HUGE, with lots of different labs and rooms for scientists to work in. Inside those labs, scientists can do all sorts of things. They could be using really powerful microscopes to look at tiny things like atoms, or they could be testing out new materials to see how strong they are or how well they conduct electricity.
It's not just the tools and equipment that make ORNL special. The people who work there are some of the smartest in the world, and they work together as a team to tackle big problems like finding new sources of clean energy or developing better ways to fight diseases.
Overall, ORNL is like a really cool science clubhouse full of brilliant scientists working hard to make the world a better and more interesting place.