  We use the S-matrix bootstrap to carve out the space of unitary, crossing
symmetric and supersymmetric graviton scattering amplitudes in ten dimensions.
We focus on the leading Wilson coefficient $\alpha$ controlling the leading
correction to maximal supergravity. The negative region $\alpha<0$ is excluded
by a simple dual argument based on linearized unitarity (the desert). A whole
semi-infinite region $\alpha \gtrsim 0.14$ is allowed by the primal bootstrap
(the garden). A finite intermediate region is excluded by non-perturbative
unitarity (the swamp). Remarkably, string theory seems to cover all (or at
least almost all) the garden from very large positive $\alpha$ -- at weak
coupling -- to the swamp boundary -- at strong coupling.
