The D-brane of dimension in type IIB string theory.
At low string coupling D1-brane/D5-brane systems are described by 2d CFT, which is well understood. After passage to the corresponding strongly coupled black brane configurations in type IIB supergravity, which are black holes in the given compactification, the entropy of these 2d CFTs matches the Bekenstein-Hawking entropy of these black holes.
This is parts of the AdS/CFT correspondence. See (AGMOO, chapter 5).
Table of branes appearing in supergravity/string theory
Chapter 5.3 of