  We study $\textrm{AdS}_2\times S^4 \times S^2 \times \Sigma_2$ solutions in
type IIB string theory arising from D1 -- D3 -- NS5 brane intersections. These
backgrounds enjoy sixteen supercharges and the corresponding internal geometry
is non-compact due to the specific form of the warping w.r.t. the Riemann
surface $\Sigma_2$. Even though a direct computation of the holographic free
energy of the would-be dual CFT$_1$ yields a divergent behaviour, it reveals
the typical $N^3$ scaling of a 6d theory upon introducing a hard cut-off. We
claim that such geometries may be interpreted as the gravity duals of M(atrix)
models describing an IR phase of the $(2,0)$ theory of M5 branes, in presence
of momentum and NUT charges. We discuss parallel $\textrm{AdS}_2$ geometries
describing longitudinal M2 branes in the UV, where the counting of the number
of degrees of freedom correctly reproduces the expected $N^{3/2}$ behaviour of
the dual field theory. These geometries provide explicit examples where
deconstructed extra dimensions yield well-defined UV descriptions in terms of
higher-dimensional CFTs.
