// This is your shape
var shape={"points":[[45.4742763586846,9.2050838470459],[45.4608530586048,9.20662879943848],[45.4518823457049,9.20070648193359],[45.4517619237449,9.19014930725098],[45.4524242413431,9.18431282043457],[45.4530263415011,9.17727470397949],[45.4616356705668,9.16414260864258],[45.4672340393048,9.16585922241211],[45.4676553994,9.1651725769043],[45.4718086375112,9.16628837585449],[45.4774059959643,9.17512893676758],[45.47644304916,9.1765022277832],[45.4780078293606,9.18113708496094],[45.4811974390469,9.18233871459961],[45.4795725661084,9.19358253479004],[45.4742763586846,9.2050838470459]],"title":"Duomo, Milan","notes":"","tags":["italy","milan"],"author":""};

// A general-purpose function to return an array of GLatLng objects from an array of [[lat,lng],[lat,lng] . .]
function makeLatLngsFromArray(a){
  var res=[];
  for(var i=0;i<a.length;i++){res[i]=new GLatLng(a[i][0],a[i][1])};
  return res;
}

// map setup
var map = new GMap2(document.getElementById("map"));
map.setCenter(new GLatLng(40.6897,-95.0446),5);
map.addControl(new GSmallMapControl());

// add the shape as a GPolygoon
var latlngs=makeLatLngsFromArray(shape.points);
var poly=new GPolygon(latlngs, '#ff0000', 3, .8, '#ff0000', .4);
map.addOverlay(poly);