ester ly ▁end ▁of ▁northern ▁Lu zon , ▁in ▁the ▁upper ▁half ▁of ▁the ▁Cord ill era ▁province ▁of ▁Ap ay ao . ▁The ▁term ▁" Is neg " ▁der ives ▁from ▁it neg , ▁meaning ▁inhabitants ▁of ▁the ▁T in eg ▁River . ▁ ▁Ap ay ao ▁der ives ▁from ▁the ▁battle ▁cry ▁Ma - ap - ay - ao ▁as ▁their ▁hand ▁is ▁cla pped ▁rapidly ▁over ▁their ▁mouth . ▁ ▁They ▁may ▁also ▁refer ▁to ▁themselves ▁as ▁Im and aya ▁if ▁they ▁live ▁up stream , ▁or ▁Im all od ▁if ▁they ▁live ▁down stream . ▁ ▁The ▁municipal ities ▁in ▁the ▁Is neg ▁domain ▁include ▁P ud tol , ▁Kab ug ao , ▁Cal anas an , ▁Flora , ▁Con ner , ▁Sta . ▁Marcel a , ▁and ▁ ▁L una . ▁Two ▁major ▁river ▁systems , ▁the ▁Ab ul og ▁River ▁and ▁the ▁Ap ay ao ▁River , ▁run ▁through ▁Isn ag ▁country . ▁▁ ▁J ars ▁of ▁bas i ▁are ▁half ▁buried ▁in ▁the ▁ground ▁within ▁a ▁small ▁shed , ▁ab ul or , ▁constructed ▁of ▁ 4 ▁posts ▁and ▁a ▁shed . ▁ ▁This ▁ab ul or ▁is ▁found ▁within ▁the ▁open ▁space , ▁lin ong ▁or ▁sid ong , ▁below ▁their ▁houses ▁( bal ay ). ▁ ▁They ▁grow ▁u pl and ▁rice , ▁while ▁also ▁pract icing ▁sw idden ▁far ming , ▁and ▁fish ing . ▁Say - am ▁was ▁an ▁important ▁ceremony ▁after ▁a ▁successful ▁head h un ting , ▁or ▁other ▁important