  We study four-dimensional black hole configurations which result from
wrapping M5-branes on a Calabi-Yau manifold, as well as U-dual realizations.
Our aim is to understand the microscopic degrees of freedom responsible for the
existence of bound states of multiple branes. The details depend on the chosen
U-frame; in some cases, they are massless string junctions. We also identify a
perturbative description in which these states correspond to twisted strings of
intersecting D3-branes at an orbifold singularity. In each case, these are the
preponderant states of the spacetime infrared conformal field theory and
account for the entropy of the blackhole.
