Abstract: While formally analogous, the thermodynamics of the de Sitter cosmological horizon is more subtle than its black hole counterpart. For example, contrary to black holes, the first law of de Sitter horizons has a minus sign indicating the entropy of a cosmological horizon is reduced by the addition of matter Killing energy. Even more, there is no asymptotic boundary in de Sitter space where thermodynamic data may be fixed to sensibly define a thermal ensemble. In this talk, I will discuss how both of these issues can be clarified by introducing a finite timelike boundary inside the de Sitter static patch. In particular, I will argue the confusion about the minus sign in the first law is due to a mistaken interpretation of the added Killing energy as the total internal energy. I will then show how this `quasi-local' thermodynamics of de Sitter space is modified by semi-classical backreaction effects in the context of the two-dimensional Jackiw-Teitelboim gravity, where  the first law becomes the statement that the generalized entropy is stationary. With time permitting, I will also show how this set-up relates to various proposals of de Sitter holography.