This course is an introduction to General Relativity – Einstein’s geometric theory of gravity. This course begins with a review of Special Relativity emphasizing the geometric aspects of the Lorentz transformations in Minkowski space-time. Using Einstein’s equivalence principle, we develop the concept of curved space-time and explain how gravity is the effect of this curving. Then we introduce the relevant mathematical tools to treat curved spaces and present the Einstein-Hilbert equation, which links the curvature to the mass (energy) density. At the end, we discuss specific solutions of Einstein-Hilbert’s equation, such as Schwarzschild’s metric.