Arab Avatar is an interesting mix of the old and new. Actually in reality I did swim in a pool that overlooked the Pyramids. But having these major features of Islamic culture on a Beach is the most Second Life of things.
On the other hand a place like Kiz Kules seems only to be Turkish because the people they chat in Turkish and there are a few Turkish flags, though the wooden houses might pass for old nice places in Istanbul
Portugal Center is one of the best executes SIMs I have ever seen, it really feels like a down town of a small city and it would be niece to see it at a crowded time.
Gopi Desert is popular with Koreans, one thing to note about Second Life is that different culture may use virtual space in different ways. For many Latin Americans I notice beaches and clubs are popular, while Koreans and Japanese like more complex RP environments. Germans I have noticed often execute very realistic and excellent look sims.
These are all off the cuff generalisations but I doubt any long term resident of Second Life would disagree that SIM take on a lot of baggage from the cultures that make them.