Tangut dharani pillars are tall pillars that were used in ancient China to spread Buddhist teachings. Imagine a really tall post that you might see holding up a big sign - it's kind of like that, but with special writing on it.
So, what's so special about this writing? Well, it was written in a language called Tangut, which is a language that was used in a part of China called the Western Xia dynasty. It's a language that not many people use anymore, so it's really unique and rare to see.
The writing on the pillars was called "dharani," which are kind of like magical spells or incantations that are supposed to protect whoever reads or hears them. They're like little prayers that Buddhists use to ask for help from a higher power.
But these pillars didn't just have writing on them - they were also really ornate and decorated with beautiful carvings and designs. They were often painted bright colors, too. So not only were they useful for spreading religious teachings, but they were also works of art.
Unfortunately, a lot of the Tangut dharani pillars that existed have been lost or destroyed over time. But the ones that still exist are really cool artifacts that teach us a lot about Chinese history and religion.