/usr/include/dune/grid/io/visual/ is in libdune-grid-dev 2.3.1-1.
This file is owned by root:root, with mode 0o755.
..
/usr/include/dune/grid/io/visual/combinedgrapedisplay.hh
/usr/include/dune/grid/io/visual/grape/
/usr/include/dune/grid/io/visual/grape/combinedgrapedisplay.cc
/usr/include/dune/grid/io/visual/grape/geldesc.hh
/usr/include/dune/grid/io/visual/grape/ghmesh.cc
/usr/include/dune/grid/io/visual/grape/ghmesh.hh
/usr/include/dune/grid/io/visual/grape/grape_undefs.hh
/usr/include/dune/grid/io/visual/grape/grapecommon.cc
/usr/include/dune/grid/io/visual/grape/grapecommon.hh
/usr/include/dune/grid/io/visual/grape/grapedatadisplay.cc
/usr/include/dune/grid/io/visual/grape/grapegriddisplay.cc
/usr/include/dune/grid/io/visual/grape/grapehmesh.hh
/usr/include/dune/grid/io/visual/grape/grapeinclude.hh
/usr/include/dune/grid/io/visual/grape/grapewrapper.hh
/usr/include/dune/grid/io/visual/grape/partitiondisplay.cc
/usr/include/dune/grid/io/visual/grapedatadisplay.hh
/usr/include/dune/grid/io/visual/grapegriddisplay.hh