Whether knowingly or coincidentally, the names of the places in Westeros and Essos seem to have similar characteristics that, when looked upon carefully, bear resemblances of the nature of the two worlds in the West and East.
The places in Westeros show an unusual similarity of their names taken directly from words associated with nature. Here are some examples:
All places are derived the language Common Tongue (equivalent of English). They are thus easily identifiable. This is in contrast to the names of places in Essos, none of which are dervied from English, and sound obscure.
The places in Essos too possess a unique similarity of ending with soft, similar sounds:
The above points can be summarised as follows:
Nature is important in Westeros: Audiences know this due to many hints in the show. The foremost is the role of seasons in Game of Thrones. The popular phrase 'Winter is Coming' captures the essence of importance of seasons. People fear the cold and its other associations (White Walkers), and prefer the summer. Westeros is also the place where resources are harvested, such as ruby (Rubyford), sapphire (The Sapphire Isles), Corn (Cornfield), and other precious stones (hence the many places with the word 'stone'). Nature is highly valued in Westeros, for it is the one factor which dominates the plots centered around the kingdom (Winter is much more powerful and deadly than the wars and kingships).
Essos is much more rooted and traditional than Westeros: Essos is a multicultural society with many traditions and roots. So far, we've seen Blacks only at Essos (Grey Worm and Missandei). We've also seen languages apart from the Common Tongue: the Dothraki language and Valyrian, both of which stemmed in Essos. There is also Asshai'l (language of Asshai), and Qartheen (language of Qarth). These roots are still present, as proved by the different languages still spoken in Essos. Essos also shows more leniency towards different classes. While lower caste people in Westeros are often seen as hungry and resenting the lords and rich, the slaves at Meereen possess a closer bond with their masters, as proved by the time when the slaves asked Daenerys to go back to their masters and fight in the pits again.
Monarchy (Westeros) vs slavery (Essos): The roots in Essos reflect the independence and freedom one finds there, away from the monarchy and ruling of Westeros. This monarchy of Westeros, controlling the entire population, is also reflected under how everyone speaks one single language, depicting a lack of independence. Westeros is deemed as a much more advanced and literate land, with more economical development, better warfare technology, etc. This is shown by location names such as Sunspear, Highgarden, Harrenhall, etc. Essos, on the other hand, believes in the ruling system used by our ancestors long before monarchy of entire nations existed: slavery. The soft endings, like -os-, connote to the lower rigidity of ruling in Essos, as compared to harsh sound endings in places in Westeros. There is a high desire for royalty, money, and of course, thrones in Westeros, while slaves and labour are more in demand in Essos.
[Bonus] Qarth: Qarth is an isolated land that marks the beginning of Daenerys's streak of conquests. The name Qarth, while a meaningless word, depicts how it is shown. The unusual name, beginning with a 'Q', a rather rare first letter for a place, goes hand in hand with the remoteness of the nation. Qarth has its own language (Qartheen), and is enclosed in huge wall boundaries, making it a stark contrast of luxury to the Red Waste lands around (Qarth is not even considered a part of Essos due to the physical distance). These features, reflected by its name, show Qarth's strive to be different and superior to other places.
Two roads diverged in a wood, and I--