Here’s something interesting I discovered recently: there are some flags of the world that have two different sides! I just assumed that all flags were identical on both sides, but apparently that’s not the case. There aren’t many, but wikipedia’s helpful entry shows them all. The first is San Juan, a province of Argentina. The front side of the flag depicts the province’s coat of arms, while the reverse simply shows a sun.
The Soviet Union’s flag was one of the most interesting to me. Most double-sided flags belonged to smaller states, provinces, and countries. The Soviet Union, however, was a large and influential nation – and its flag had two sides!
Three American states have had double-sided flags at one point or another – Alabama in 1861, Massachusetts from 1908-1971 – but Oregon is the only state that still has a flag with two sides. Most double-sided flags differ little between the two sides, but the reverse of Oregon’s flag is almost completely different from the front.
For the whole list of double-sided flags, check out this Wikipedia article.