First Day of Issue = May 13, 1939
Size: 33.00 mm x 28.00 mm
Quantity printed = 1,300,000
Perforated 10.00 x 11.50
Print method: Lithography

Stamp issued for the 5th anniversary of the 1934 Latvian coup d'état. This stamp shows the Riga Castle.

Catalog numbers
Scott 209
Michel LV 273

For more information check out the links below
1934 Latvian coup d'état
Riga Castle (Wikipedia)