/usr/include/geos/operation/overlay/ is in libgeos-dev 3.2.2-3ubuntu1.
This file is owned by root:root, with mode 0o755.
..
/usr/include/geos/operation/overlay/EdgeSetNoder.h
/usr/include/geos/operation/overlay/ElevationMatrix.h
/usr/include/geos/operation/overlay/ElevationMatrixCell.h
/usr/include/geos/operation/overlay/FuzzyPointLocator.h
/usr/include/geos/operation/overlay/LineBuilder.h
/usr/include/geos/operation/overlay/MaximalEdgeRing.h
/usr/include/geos/operation/overlay/MinimalEdgeRing.h
/usr/include/geos/operation/overlay/MinimalEdgeRing.inl
/usr/include/geos/operation/overlay/OffsetPointGenerator.h
/usr/include/geos/operation/overlay/OverlayNodeFactory.h
/usr/include/geos/operation/overlay/OverlayOp.h
/usr/include/geos/operation/overlay/OverlayResultValidator.h
/usr/include/geos/operation/overlay/PointBuilder.h
/usr/include/geos/operation/overlay/PolygonBuilder.h
/usr/include/geos/operation/overlay/snap/
/usr/include/geos/operation/overlay/snap/GeometrySnapper.h
/usr/include/geos/operation/overlay/snap/LineStringSnapper.h
/usr/include/geos/operation/overlay/snap/SnapIfNeededOverlayOp.h
/usr/include/geos/operation/overlay/snap/SnapOverlayOp.h