Nim Dorji lives in Damphu region, but came originally from Paro Dzongkhag. He gives an account of an iron bridge near Teru Bja (money cliff). The bridge was constructed by Thangthong Gyelpo, an iron bridge master and expert blacksmith who traveled through much of Bhutan. Today the bridge is submerged under the river bank as it suffered with the passage of time. According to Nim Dorji, it was said that the sacred irons are already owned by the mermaid of that place. His father, Dobji Penlop (governer of Dobji region in Paro), had tried to collect iron from the bed of river, but unsuccessfully. A few pieces of this irons are collected and can be seen at Silu Gönpa in Paro Dzongkhag.