We will prove the Stark-Heegner Theorem by counting the j invariants of elliptic curves corresponding to integral points of $X_{ns}^n(7)$, following Kenku's work in 1984. On our way, we will mention arithmetic properties of Klein Quartic, primitive solutions to $x^2+y^3=z^7$ and finally explain why Stark-Heegner Theorem is equivalent to the fact that only Fibonacci numbers that are perfect cubes are 0,1 and 8.