I include an entry for Riobamba mainly for the journey there. The direct road between Baños and Riobamba is frequently closed due to the constant volcanic activity of Tungurahua.

I can see why. I'm not actually convinced it was officially open when we took it, particularly for poorly maintained coaches. Some of the road was intact, but a lot of it had been 'washed' away by lava flows and made (barely) passable by bulldozers flattening the lava into a fine dusty sand. There were some very hairy moments as we crept along extremely narrow dust tracks on steep mountain sides with severe drops to the side. Apparently recent landslides did not provide much comfort.

The fact that the bus left 20 mins late and so the driver was clearly trying to make up time did nothing to help.

It wouldn't class as one of the world's most dangerous roads, but to a novice it was pretty scary. The front row seats were not appreciated!
Anyway, we arrived safely in Riobamba, Ecuador's third largest town apparently, and the gateway to the infamous Devil's Nose train journey.