It is also the minting authority for the Bhutanese Ngultrum. The restoration works were undertaken at an estimated cost of 135 million ngultrum. Bhutan's currency is the ngultrum, whose value is fixed to the Indian rupee. The ngultrum is currently pegged to the Indian rupee at parity. Both the Nepalese rupee and Bhutanese ngultrum are pegged with the Indian rupee.