In the courtyard of the temple we noticed a pile of iron links. These had been forged by Bhutan’s 15th century bridge builder, Thanktong Gyalpo. According to our guide “he built 108 iron bridges. He was the one who originated the use of iron chains in making suspension bridges.” None of those remains standing, but the iron from one of them was used in a bridge we were shown later that day.

Photo essay: Journey to enigmatic Bhutan