Savannah monitors come from the semi-arid regions of Africa. Thus, they have little need for high humidities, and do well in low-middle humidity levels. A hot spot that reaches 90-100 degrees is needed, but do not maintain the entire cage at these temperatures. Savannahs need a place to cool off in the 80s. A Savannah monitor cage, like all monitor cages, must be large.
Savannah monitors are extremely active and curious.
They will explore and investigate everything in their territory. Thus, simplicity should be the rule. Savannahs are not aboreal once they are bigger, so branches for climbing are unnecessary. If, however, they are kept for asthetic reasons, they should be large and sturdy. Plants, real or fake, will simply be knocked over or destroyed, so it is best to avoid them.