I also looked at the blast door map on Lostpedia yesterday and noticed what looked like tunnels between the Dharma stations.
But what stood out to me was that the notations on the map were enlarged and some of them were in LATIN!
Makes me think that Radzinsky may have drawn the original map, but the Others were adding stuff to it, as they discovered what the Dharma Initiative built on the island?
Who else speaks Latin but Others?