/usr/include/CGAL/Mesh_2/ is in libcgal-dev 4.11-2build1.
This file is owned by root:root, with mode 0o755.
..
/usr/include/CGAL/Mesh_2/Clusters.h
/usr/include/CGAL/Mesh_2/Do_not_refine_edges.h
/usr/include/CGAL/Mesh_2/Face_badness.h
/usr/include/CGAL/Mesh_2/Lipschitz_sizing_field_2.h
/usr/include/CGAL/Mesh_2/Lloyd_move_2.h
/usr/include/CGAL/Mesh_2/Mesh_global_optimizer_2.h
/usr/include/CGAL/Mesh_2/Mesh_sizing_field.h
/usr/include/CGAL/Mesh_2/Output_stream.h
/usr/include/CGAL/Mesh_2/README
/usr/include/CGAL/Mesh_2/Refine_edges.h
/usr/include/CGAL/Mesh_2/Refine_edges_visitor.h
/usr/include/CGAL/Mesh_2/Refine_edges_with_clusters.h
/usr/include/CGAL/Mesh_2/Refine_faces.h
/usr/include/CGAL/Mesh_2/Sizing_field_2.h
/usr/include/CGAL/Mesh_2/Uniform_sizing_field_2.h