/usr/include/CGAL/Apollonius_graph_2/ is in libcgal-dev 4.2-5ubuntu1.
This file is owned by root:root, with mode 0o755.
..
/usr/include/CGAL/Apollonius_graph_2/Apollonius_graph_2_impl.h
/usr/include/CGAL/Apollonius_graph_2/Apollonius_graph_hierarchy_2_impl.h
/usr/include/CGAL/Apollonius_graph_2/Bounded_side_of_ccw_circle_C2.h
/usr/include/CGAL/Apollonius_graph_2/Compare_weight_2.h
/usr/include/CGAL/Apollonius_graph_2/Compare_x_2.h
/usr/include/CGAL/Apollonius_graph_2/Compare_y_2.h
/usr/include/CGAL/Apollonius_graph_2/Constructions_C2.h
/usr/include/CGAL/Apollonius_graph_2/Constructions_ftC2.h
/usr/include/CGAL/Apollonius_graph_2/Constructions_rtH2.h
/usr/include/CGAL/Apollonius_graph_2/Delage_traits/
/usr/include/CGAL/Apollonius_graph_2/Delage_traits/Apollonius_graph_mixed_filtered_traits_2.h
/usr/include/CGAL/Apollonius_graph_2/Delage_traits/Apollonius_graph_mixed_traits_2.h
/usr/include/CGAL/Apollonius_graph_2/Delage_traits/Apollonius_graph_new_filtered_traits_2.h
/usr/include/CGAL/Apollonius_graph_2/Delage_traits/Apollonius_graph_new_traits_2.h
/usr/include/CGAL/Apollonius_graph_2/Delage_traits/Conflict_2.h
/usr/include/CGAL/Apollonius_graph_2/Delage_traits/Edge_conflict_2.h
/usr/include/CGAL/Apollonius_graph_2/Delage_traits/Finite_edge_conflict_2.h
/usr/include/CGAL/Apollonius_graph_2/Delage_traits/Infinite_edge_conflict_2.h
/usr/include/CGAL/Apollonius_graph_2/Delage_traits/New_predicates_C2.h
/usr/include/CGAL/Apollonius_graph_2/Delage_traits/Orientation_2.h
/usr/include/CGAL/Apollonius_graph_2/Delage_traits/Vertex_conflict_2.h
/usr/include/CGAL/Apollonius_graph_2/Finite_edge_test8_C2.h
/usr/include/CGAL/Apollonius_graph_2/Finite_edge_test_C2.h
/usr/include/CGAL/Apollonius_graph_2/Incircle8_C2.h
/usr/include/CGAL/Apollonius_graph_2/Incircle_C2.h
/usr/include/CGAL/Apollonius_graph_2/Infinite_edge_test_C2.h
/usr/include/CGAL/Apollonius_graph_2/Is_degenerate_edge_C2.h
/usr/include/CGAL/Apollonius_graph_2/Is_hidden_C2.h
/usr/include/CGAL/Apollonius_graph_2/Kernel_wrapper_2.h
/usr/include/CGAL/Apollonius_graph_2/Orientation8_C2.h
/usr/include/CGAL/Apollonius_graph_2/Orientation_2.h
/usr/include/CGAL/Apollonius_graph_2/Oriented_side_of_bisector_C2.h
/usr/include/CGAL/Apollonius_graph_2/Predicate_constructions_C2.h
/usr/include/CGAL/Apollonius_graph_2/Predicates_C2.h
/usr/include/CGAL/Apollonius_graph_2/Traits_wrapper_2.h
/usr/include/CGAL/Apollonius_graph_2/basic.h
/usr/include/CGAL/Apollonius_graph_2/check_filter.h
/usr/include/CGAL/Apollonius_graph_2/comparator_profiler.h
/usr/include/CGAL/Apollonius_graph_2/compare_quadratic.h
/usr/include/CGAL/Apollonius_graph_2/predicate_profiler.h
/usr/include/CGAL/Apollonius_graph_2/uncertain/
/usr/include/CGAL/Apollonius_graph_2/uncertain/Apollonius_graph_uncertain_filtered_traits_2.h
/usr/include/CGAL/Apollonius_graph_2/uncertain/Uncertain_is_hidden_C2.h
/usr/include/CGAL/Apollonius_graph_2/uncertain/Uncertain_oriented_side_of_bisector_C2.h
/usr/include/CGAL/Apollonius_graph_2/uncertain/Uncertain_vertex_conflict_2.h
/usr/include/CGAL/Apollonius_graph_2/uncertain/uncertain_functions_on_signs.h