All great-circle paths lead to Rome

    lon  = 12.50
    lat  = 41.99
    Gdist = gmt("grdmath -Rg -I1 12.5 41.99 SDIST")

    coast(region=:global, land=:lightgreen, ocean=:blue, area=1000,
         frame=(grid=30, title="Distances from Rome to the World"),
         shore=:thinnest, proj=(name=:Hammer, center=90),
         figsize=20, portrait=false)
    grdcontour!(Gdist, annot=(int=1000, labels=(curved=true, unit="\" km\"",
                font="white")), labels=(line="Z-/Z+",), smooth=8, cont=500,
                pen=((contour=true,pen="thinnest,white,-"),
                (annot=true, pen="thin,white")) )

    # Location info for 5 other cities + label justification
    cities = [105.87 21.02; 282.95  -12.1; 178.42 -18.13; 237.67 47.58; 28.20 -25.75];
    just_names = ["LM HANOI", "LM LIMA", "LM SUVA", "RM SEATTLE", "LM PRETORIA"];
    D = text_record(cities, just_names)

    # For each of the cities, plot great circle arc to Rome with gmt psxy
    plot!([lon lat; 105.87 21.02], lw=:thickest, lc=:red)
    plot!([lon lat; 282.95 -12.1], lw=:thickest, lc=:red)
    plot!([lon lat; 178.42 -18.13],lw=:thickest, lc=:red)
    plot!([lon lat; 237.67 47.58], lw=:thickest, lc=:red)
    plot!([lon lat; 28.20 -25.75], lw=:thickest, lc=:red)

    # Plot red squares at cities and plot names:
    plot!(cities, marker=:square, ms=0.2, fill=:red, markerline=:thinnest)
    text!(D, offset=(away=true, shift=(0.15,0)), font=(12,"Courier-Bold",:red),
          justify=true, no_clip=true)

    # Place a yellow star at Rome
    plot!([12.5 41.99], marker=:star, ms=0.5, fill=:yellow, ml=:thin)

    # Sample the distance grid at the cities and use the distance in km for labels
    dist = grdtrack(Gdist, D);
    text!(dist, offset=(0, -0.5), noclip=true, fill=:white, pen=true, clearance=0.05,
          font=(12,"Helvetica-Bold"), justify=:CT, zvalues="%.0f", show=true)