Abstract: In Schwarzschild spacetime with positive mass $M$, there exist (unstable) circular orbits of trapped null geodesics at the Schwarzschild radius $r=3M$, outside the black hole horizon at $r=2M$. These orbits fill a three-dimensional submanifold $S^2\times \mathbb R$ called the photon sphere of the Schwarzschild spacetime. In general, a region in spacetime that is a union of all trapped null geodesics is called the Trapped Photon Region (TPR) of spacetime. In this seminar, we will consider three models of stationary, axisymmetric (sub-extremal and extremal) black hole spacetimes: Kerr, Kerr-Newman, and Kerr-Sen. We will see that, unlike the TPR of Schwarzschild spacetime, the TPR in such spacetimes is not a submanifold of the spacetime in general. However, its canonical projection in the (co-)tangent bundle is a five-dimensional submanifold of topology $SO(3)\times\mathbb R^2$. This result has potential applications in various problems in mathematical relativity. The talk is based on the paper by Cederbaum and Jahns (2019), where they prove the result in Kerr spacetime, and by Cederbaum and myself (under preparation), where we extend this result to the remaining two abovementioned spacetimes.