I agree that this is coin collecting at its best; the coins as portals to more knowledge and beter understanding. It is difficult to come up with more, but I did find yet another one. Through several types, Thailand has put the
Phra Pathom Chedi on the reverse of its 5 satang coins. In spite of their very low denomination, these coins are somewhat difficult to find, since they no longer circulate in Thailand and dealers won't carry them because of their low catalogue quote. Since I don't have a copy, I borrowed one, date 2550 BE (2008 AD) from Wikipedia.
Peter