agriculture in ancient Tamil country
...that the Kallanai dam, built by Karikala Chola to support agriculture in ancient Tamil country, is considered the oldest water-regulation structure still in use?
...that the <a class="mw-redirect" href="./Kallanai" id="mwCwA" rel="mw:WikiLink" title="Kallanai">Kallanai</a> dam, built by <a class="mw-redirect" href="./Karikala_Chola" id="mwCwE" rel="mw:WikiLink" title="Karikala Chola">Karikala Chola</a> to support <b id="mwCwI"><a class="mw-redirect" href="./Agriculture_in_Ancient_Tamil_Country" id="mwCwM" rel="mw:WikiLink" title="Agriculture in Ancient Tamil Country">agriculture in ancient Tamil country</a></b>, is considered the oldest water-regulation structure still in use?