The Drinfeld upper half-plane is the p-adic analogue of the complex upper half-plane. It is a rigid analytic space and may be expressed as $\mathbb{P}^{1}(\mathbb{C}_{p})\setminus \mathbb{P}^{1}(\mathbb{Q}_{p})$. There is also a function-field analogue of the construction, also referred to as the Drinfeld upper half-plane.