Can't fly to Mandalay, must go to Yangoon, it's then 15 hours on a bus to Mandalay, 6 hours from Mandalay to an interim town than another three to Bagan, all on decrepit Burmese buses.

 

When you get there it's hot, 45-50 degrees. It was abandoned by the locals just before the Mongols arrived. The Mongols took it then mysteriously didn't want to stay and left. It's considered a great historical mystery why the Mongols left the place so rapidly. If you have encountered the  overwhealming heat (and I lived in the hottest city in the world for 5 years) it's no surprise why these temperature climate horsemet left.

 

It is spread out over hundreds of square miles and the temples not a walkable distance from each other. The Burmese have a moronically braindead law, foreigners can't ride motorcycles in Bagan, (Burmese can) even as a passenger. So Burmese tourists hire motorcycle taxis who take them from site to site. Tourists are left with horse drawn cart taxis, common in most Burmese cities (in the countryside it's bufffalo cart taxis) except Yangoon and Mandalay, or hiring bicycles. I hired a bicycle as they are faster than horse drawn cart taxis, trouble is they are in such a poor state of repair they puncture ever 2-3 kilometres and strand you. There is no such thing as repairing a puncture, they just pump up the tired and it goes down again in an hour or two. All bicycle are hired out with existing slow punctures. Bagan is a nice place, but it is completely outclassed by Angkor, that coupled with the transport problems I'd say Angkor or even the Plain of Jars is a better spend till the Burmese government get a brain and amend the transport laws.