Fig 1.
(A) The north-eastern Adriatic regions with the position of the studied Trieste Karst sector and the indication of the main localities mentioned in the text (B). Maps were created with QGIS version 2.14.0 (http://www.qgis.org/it/site/).
Fig 2.
(A) Geomorphological and archaeological map of the investigated area (within the black irregular contour line). (B) LiDAR-derived hillshade of the area close to Grociana piccola Roman fortifications showing the possible road tracks (indicated by black arrows) cut by dolines 1–2; location of geophysical investigations is indicated by violet lines. Maps were created with ARCMAP version 10.2.1 (http://desktop.arcgis.com/en/arcmap/) and QGIS version 2.14.0 (http://www.qgis.org/it/site/).
Fig 3.
LiDAR-derived map of doline 1 cutting the putative road tracks and related topographic profiles.
Map and profiles were created with QGIS version 2.14.0 (http://www.qgis.org/it/site/).
Fig 4.
(A) 3D perspective view of the Wenner-Schlumberger ERT inverted profiles, crossing doline 1. The resistivity scale has been divided into three main categories, respectively interpreted as the doline filling materials, the limestone bedrock, and a possible cave. The dotted lines mark low resistivity zones within the limestone. The vertical to horizontal scale ratio is equal to one. (B) GPR-derived 3D volume of the investigated road stretch. (C) GPR-derived interpreted 2D profile. The light-blue line images the road track, while the yellow ellipses mark its borders. Green and yellow segments highlight the limestone layering while red lines refer to local opposite dipping surfaces probably related to main fractures. R and L lie in the "road" and "limestone" domains, respectively. For the location of geophysical investigations see Fig 2B.
Fig 5.
Typology and distribution of Roman shoe hobnails and identified archaeological features.
(A) Typology of Roman shoe hobnails. Drawings by A. Fragiacomo. (B) Probable ancient road remains (black lines) and the distribution of the Roman shoe hobnails (S4–S8 Figs) found in the surveyed area (red dots). The main archaeological sites (green lines and symbols) and probable traces of Roman land division (brown lines) are shown in the map too. Areas of particular interest highlighted in the green rectangles are shown in detail in the Supporting information. Small green square: Merišce Roman site [26]. Map was created with QGIS version 2.14.0 (http://www.qgis.org/it/site/) with contour lines at 5 m.
Fig 6.
Landscape evolution in the investigated area.
(A) 3D LiDAR-derived hillshade showing the main archaeological features. (B) The road path during the Roman time. (C) The present state of the road traces, cut by dolines 1–2 (in red) and the modern road Trieste-Rijeka (in blue).