Our first day of sightseeing took us to the site of a prehistoric sea. These narrow haystack shaped hills were islands for millions of years and the seawater eroded the limestone below the surface into the honeycombed format that you see. Only Vietnam has similar hills. As the sea receded, the flat land retained much of the nutrients and we saw that it was mostly farmed. In the very first photo, you can see another view from this same vista behind Barb and I.