  Starting from the isomorphism between the AdS Carroll and Poincar\'e
algebras, we map the three-dimensional asymptotically flat solutions of
Poincar\'e gravity into an AdS Carroll spacetime. We show the mapped solutions
satisfy the field equations of the Chern-Simons formulation of AdS Carroll
gravity and exhibit a Carroll geometry structure. Despite the presence of a
negative cosmological constant in the mapped spacetime, the algebra of the
canonical generators of the asymptotic symmetries is given by the
$\mathfrak{bms}_3$ algebra.
