Located in the center of Burma and rising to 1500 meters, Mount Papa is an unusual, unique site, and can be worth a visit, as long as you ignore the details that spoil it. After climbing for half an hour, evading the assaults of the water bottle stealing monkeys (keep your provisions in your bags: the monkeys are not at all friendly but actually quite aggressive!), you will arrive at the golden temple of Taung Kalat. The building itself is richly decorated, but what a disappointment when you approach the mountain's flanks: incredible as it may seem, they're actually covered in litter! It's a real shame to able to see this sad spectacle from such a holy place.
In my opinion, Mount Popa, which is one of the major sites of Buddhism, does not live up to the publicity produced by the agencies that offer excursions to it. Go and see Mount Popa if you've set aside more time than you need to visit the region. For me, the site is not one of the essential places to visit in order to enjoy a successful trip to Burma. One positive aspect however: you will find it cooler and fresher there than in Bagan.
The climb is really worth it, especially if you are in Bagan. You can go on half-day excursions to Mount Popa. Most hotels have it on offer. The view from the summit of the mount is really worthwhile, weather permitting. On your way there, between Baga and Mount Popa, you may stop to visit a palm wine factory as well as a sugarcane factory.
During your climb, aside from dirt on the ground, you need to watch out for monkeys, who like to steal backpacks, plastic bags, food supplies and even sun glasses!
Anyone in good physical condition will find it easy to climb the 777 steps; at any rate it will not be too difficulty.