2 Euros Physics

San Marino issued this coin as part of its annual commemorative 2 euro program, which the republic uses aggressively — releasing new designs nearly every year, a privilege afforded to microstates under their minting agreements with the European Central Bank. The 2005 piece honored the World Year of Physics, a UNESCO-designated centenary marking a hundred years since Einstein published four papers in 1905 that reshaped the discipline. San Marino's total authorized mintage for commemorative 2 euro issues is tightly capped, making its annual releases consistently scarcer than equivalent issues from larger eurozone members.