  Quantum gravity (QG) has a natural cutoff given by the Planck scale $M_{\rm
pl}$. However, it is known that the EFT of gravity can break down at a lower
scale, the species scale $\Lambda_s\lesssim M_{\rm pl}$, if there are light
species of particles. Here we point out that there is a third scale
$\Lambda_{\rm BH}\lesssim \Lambda_s\lesssim M_{\rm pl}$, which marks the
inverse length (or the temperature) of the smallest black hole where the EFT
gives a correct description of its entropy and free energy. This latter scale
is hard to detect from the viewpoint of EFT as it represents a phase transition
to a state with lower free energy. We illustrate this using examples drawn from
consistent QG landscape. In particular $\Lambda_{\rm BH}$ gets related to
Gregory--Laflamme transition in the decompactification limits of quantum
gravity and to the Horowitz--Polchinski solution in the light perturbative
string limits. We propose the existence of $\Lambda_{\rm BH}$ marking the
temperature at which neutral black holes undergo a phase transition, as a new
Swampland condition for all consistent quantum theories of gravity. In the
asymptotic regimes of field space $\Lambda_{\rm BH}$ is close to the mass scale
of the lightest tower but deviates from it as we move inwards in the moduli
space.
