The Mingun Pahtodawgyi Pagoda (also called Mingun Pagoda & Mantara Gyi Pagoda) that you see today is just the base of what would have been a stupendous monument.
Construction of Mingun Pahtodawgyi started in 1799 and ceased in 1819 with the death of King Bodawpaya. After 20 years only the outer terraces and the huge base had been finished. The building suffered major damage in the 1839 and subsequent earthquakes but has so far remained standing.
If you start at the front right corner of the pagoda there is a stairway with handrail that you can climb about two thirds of the way to the top for terrific views. It is not possible to climb all the way to the top as the pagoda has suffered too much earthquake damage in the past. It is deemed too dangerous to go further up. Even from this height you get great views and photo opportunities.
After you descend the stairway go to the one functioning small shrine in the middle of the front wall that is maintained by the local Bhuddist monks. There is a little ornate bell on the terrace outside the shrine.
After that you can walk around the 450 foot square terrace and see the whole pagoda from different angles, it is very photegenic. The upper terraces right against the structure are not walkable as they are full of debris, however the lower terrace is an easy walk. From the sides and the rear you can see where the earthquakes have rent great tears in the building structure.
Besides the main shrine at the front, each side of the structure also has a large niche in it that would have been for similar shrines, or doorways to the interior. You can walk up from the main terrace to these spots. It has been reported that there was a shrine in the main internal chamber which housed a sacred Bhudda relic but the chamber collapsed during the 1839 earthquake.
As you circle around the massive structure you can see the outer wall that encompasses the pagoda. Each side has one main entrance and two smaller ones, the main one is directly opposite the shrine in each wall.
There is a small local market at the front of Mingun Pahtodawgyi. If you are looking for a practical souvenier check out the hand woven water bottle holders, very handy. There is also a more upmarket set of shops running down an alley beside the pagoda.
From Mingun Pahtodawgyi Pagoda head North up the main street 100m to the Mingun Sayadaw memorial pagoda.