The National Fire Research Laboratory is a unique-in-the-world research facility for conducting real-scale fire-structure experiments under fires as large as 20 MW with controlled structural loading and over a range of length scales and geometries, from small structural elements or assemblies to full-scale buildings two stories in height and 2 x 3 bays in plan. Current research focuses on the effect of structure on fire dynamics, the advancement on real-scale fire metrology, the effect of fire on structure performance, sensing technology for monitoring structural performance in fires, and similitude and scaling in fires.