Sentence:  We landed at the head of Garden Island, which is situated near the middle of the river and on the <WSD>lip</WSD> of the Falls. On reaching that <WSD>lip</WSD>, and peering over the giddy height, the wondrous and unique character of the magnificent cascade at once burst upon us. 
Meaning of the word marked with <WSD> tags:  The edge of a high spot of land.