22 May (Poland ) within release Polish Scientific Expedition goes into circulation Stamp Caverns,Map of Cuba face value 2 Polish złoty
Stamp Caverns,Map of Cuba in catalogues | |
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Michel: | Mi:PL 2687 |
Stamp Number: | Sn:PL 2390 |
Stamp is horizontal format.
Also in the issue Polish Scientific Expedition:
Stamp Caverns,Map of Cuba it reflects the thematic directions:
A cave or cavern is a natural void in the ground, specifically a space large enough for a human to enter. Caves often form by the weathering of rock and often extend deep underground. The word cave can refer to smaller openings such as sea caves, rock shelters, and grottos, that extend a relatively short distance into the rock and they are called exogene caves. Caves which extend further underground than the opening is wide are called endogene caves