This paper presents a microscopic derivation of black hole entropy based on the near-horizon geometry of black holes that are locally $ AdS_3 $. The authors show that quantum gravity on $ AdS_3 $ is equivalent to a conformal field theory (CFT), and use this to compute the black hole entropy from the asymptotic growth of states. The result agrees precisely with the Bekenstein-Hawking area formula for entropy, and applies to any consistent quantum theory of gravity, without relying on string theory or supersymmetry. The paper begins by reviewing the results of Brown and Henneaux, who showed that the asymptotic symmetry group of $ AdS_3 $ is generated by the Virasoro algebra. This implies that any consistent quantum theory of gravity on $ AdS_3 $ is a CFT. The central charge of this CFT is calculated as $ c = \frac{3\ell}{2G} $, where $ \ell $ is the AdS radius and $ G $ is Newton's constant. The paper then discusses the BTZ black hole, a well-known example of a black hole with near-horizon geometry $ AdS_3 $. The entropy of the BTZ black hole is computed using the Cardy formula for the asymptotic growth of states in a CFT. The result matches the Bekenstein-Hawking formula exactly. The paper also considers other examples of black holes with near-horizon geometry $ AdS_3 $, including black strings in six dimensions and four-dimensional extremal charged black holes. These examples show that the microscopic derivation of black hole entropy applies to a wide range of black holes. The paper concludes by discussing the relation between this derivation and previous results in string theory and other approaches to black hole entropy. It also highlights the connection between the CFT description of black hole microstates and the holographic principle. The results show that the black hole entropy can be understood as the entropy of a CFT living on a $ (1+1) $-dimensional cylinder surrounding the black hole, with no information loss.This paper presents a microscopic derivation of black hole entropy based on the near-horizon geometry of black holes that are locally $ AdS_3 $. The authors show that quantum gravity on $ AdS_3 $ is equivalent to a conformal field theory (CFT), and use this to compute the black hole entropy from the asymptotic growth of states. The result agrees precisely with the Bekenstein-Hawking area formula for entropy, and applies to any consistent quantum theory of gravity, without relying on string theory or supersymmetry. The paper begins by reviewing the results of Brown and Henneaux, who showed that the asymptotic symmetry group of $ AdS_3 $ is generated by the Virasoro algebra. This implies that any consistent quantum theory of gravity on $ AdS_3 $ is a CFT. The central charge of this CFT is calculated as $ c = \frac{3\ell}{2G} $, where $ \ell $ is the AdS radius and $ G $ is Newton's constant. The paper then discusses the BTZ black hole, a well-known example of a black hole with near-horizon geometry $ AdS_3 $. The entropy of the BTZ black hole is computed using the Cardy formula for the asymptotic growth of states in a CFT. The result matches the Bekenstein-Hawking formula exactly. The paper also considers other examples of black holes with near-horizon geometry $ AdS_3 $, including black strings in six dimensions and four-dimensional extremal charged black holes. These examples show that the microscopic derivation of black hole entropy applies to a wide range of black holes. The paper concludes by discussing the relation between this derivation and previous results in string theory and other approaches to black hole entropy. It also highlights the connection between the CFT description of black hole microstates and the holographic principle. The results show that the black hole entropy can be understood as the entropy of a CFT living on a $ (1+1) $-dimensional cylinder surrounding the black hole, with no information loss.