  We show that on every ${\sf RCD}$ spaces it is possible to introduce, by a
distributional-like approach, a Riemann curvature tensor.
  Since after the works of Petrunin and Zhang-Zhu we know that finite
dimensional Alexandrov spaces are ${\sf RCD}$ spaces, our construction applies
in particular to the Alexandrov setting. We conjecture that an ${\sf RCD}$
space is Alexandrov if and only if the sectional curvature - defined in terms
of such abstract Riemann tensor - is bounded from below.
