Although Yangon is a very interesting city, I like cities which retain part of their past, although, as in the case of Yangon, this legacy has not been restored in 60 years. The main colonial era buildings are spread near the river, where they were customs and colonial buildings where officials worked in what was then a thriving commercial metropolis for its navigable river. Some buildings in the main square are next to each other like the clock tower, and you should visit Aung San market.
The centre of Yangon is not a square, but the confluence of four streets. In the middle, there is the Sule Pagoda which isn't round, but octagonal plan that is transmitted to the pagoda. This is also kilometre zero for all the roads leaving towards the north of the country. Also in this plaza is the City Hall and the Monument of Independence. It has devilish traffic and luckily you aren't allowed to ride by motorcycle in the circular, if not, it would be really crazy.