The Hukou Waterfall (壶口瀑布 [Hǔkǒu Pùbù]; Teapot Waterfall or Tea Kettle Spout Waterfall) is one of those waterfalls that's got volume and power instead of gaudy dimensions. This waterfall also struck us as unusual because of its yellowish appearance because it resided directly on the Yellow River (黄河 [Huǎng Hé]), China's second longest river. And in settings that were mostly arid desert lands very reminiscent of the Colorado River in the American Southwest, having the river meader through such seemingly harsh climates made this waterfall all the more memorable (not to mention the amount of work it took to get here in the first place).
The falls is actually shared between both the Shaanxi [陕西; Shǎnxī] Province (the same one that has the famous Terracota Soldiers [兵马俑; Bīng mǎ yóng] in Xi'an [西安; Xī'ān]) as well as the Shanxi [山西; Shānxī] Province since the Yellow River defines their shared mutual border. I think it's definitely worth checking out the falls on both sides of the river for the full experience.
Unfortunately for us, we were only able to see the falls from the Shaanxi side because the bridge to the other side was under construction, and we were running too short on time to make the long detour we would've had to take. So we really can't say anything from personal experience regarding the Shanxi side. But from looking at the overlooks across the river and imagining what the view would be like, the Shanxi side looked to have more frontal views of the falls. There was even a path that led down steps (possibly through either a tunnel or narrow passageway) to a lower viewpoint looking almost face up with the falls. The Shaanxi side (which was all we got to experience) had more top down and comprehensive views.
In January 2009, unprecedented ice flows occurred on the Yellow River that caused the closure of this attraction until early April. We were lucky to see the falls a month after it re-opened, but we could still see most of the lower viewpoints remained closed. And that was probably the main reason why we couldn't take the nearest bridge across to the other side.
The "teapot" or "tea kettle" metaphor was said to come from the pressure that built up and got released through the spout as one would be brewing tea. I guess they thought of the similar kind of turbulence and pressure when the Yellow River got squeezed into a narrow gorge from which this waterfall made its dramatic appearance.
I'm betting that the falls is at its highest flow when floods arrive during the Summer rains combined with melting snow from the Yellow River's origins on the Tibetan Plateau.
For all intents and purposes, we considered this to be pretty much a roadside waterfall even though we did have to make a brief walk to get right up to the edge of the river's bank next to the falls.
Directions: As for getting to Hukou Waterfall, even though it's possible to make a long day trip out of Xi'an, it's actually a bit of a stretch as you're looking at over 5-6 hours of driving each way (traffic notwithstanding; trust us on this one!). To keep us occupied, we did notice quite a few of what appeared to be cave dwellings en route.
Perhaps a more reasonable option would be to base yourself for a night out of a closer town or one of the hotels we saw on the Shanxi side (note: Taiyuan, Shanxi's capital, looks like it's also some 300km away). So either way, this waterfall is quite remote and requires a bit of effort to access.
Part of the challenge of getting to the Hukou Waterfall was fighting traffic to extradite ourselves from the city of Xi'an. The construction work on the public transport system here didn't help matters (but I suppose it was a smart move in the long run on their part).
Cave dwellings on the cliffs I think during the long drive from Xi'an to the Hukou Waterfall
Some Chinese tourists getting their photos of the falls
A rainbow was present when we were there
Looking further downstream at another smaller waterfall
View of the Hukou Waterfall as seen from the car park
Since we were based in Xi'an on this leg of the trip, of course we had to see the Terracota Soldiers