Poland / Polish / abbr. for 波蘭|波兰[Bo1 lan2]
波
=
氵
+
皮
:
Before entering observatory every visitor has to take off their shoes, so there are a lot of leather shoes (皮) in front of the observatory (o1). Beelzebub (b) cannot miss the opportunity to make a huge wave (波) by pouring his water bottle (氵) and to flush away all the shoes.