"Starting from Keelung, we passed the cliffs of Santiaoling, hearing no birds. It was a journey that carts and horses could not make. Then we used vines to ascend, and in three days we reached Su-ao ...." In the National Palace Museum files Ding Richang gives detailed descriptions of what was then wilderness.
「先由雞籠啟途，過三貂嶺、懸崖峭壁，禽鳥聲絕，輿馬所不能通，則攀藤援葛而上，三日抵蘇澳… …」，故宮檔案《丁日昌傳稿》中，對當時未開發前的台灣地理，有很精彩的描述。