100 Ngultrum

Bhutan's first banknote series, of which this 100 Ngultrum is the highest denomination, was introduced following the establishment of the Royal Monetary Authority in 1982 — except it wasn't. The notes actually predate the RMA entirely, issued directly under the Royal Government when Bhutan had no formal central bank. The currency itself, the ngultrum, was introduced at par with the Indian rupee, a peg that remains in force today and has made the ngultrum's practical independence largely symbolic.

Pick 4 is scarce in any grade. Bhutan's tiny population and limited formal banking infrastructure meant print runs were small, and the Indian rupee continued to circulate freely alongside it.