500 Riels

Pick 16 was issued during the Khmer Republic period, the short-lived pro-American government that replaced Sihanouk following the 1970 coup. The Banque Nationale du Cambodge continued issuing notes under Thomas De La Rue through these years, but the entire monetary system collapsed in April 1975 when the Khmer Rouge took Phnom Penh and abolished currency entirely — every bank was closed, and the national reserves were destroyed or abandoned.

Notes from this series found in circulation grades are genuinely scarce; the abolition came so abruptly that large stocks were simply discarded rather than systematically redeemed. The watermark security feature is a De La Rue standard inclusion for the period.