I try to go to places where I will find Spanish words I don't know. Today, I read passages from the Holy Bible in Spanish. There were a lot of words there that I didn't know. So everything was new to me. The words were like little mysteries I had to solve.
What is this word? What does it mean? Also, there was the satisfaction of finding out and knowing what the words meant. I looked in the Book of Proverbs which is chock full of these mystery words. Two words I really liked were "colinas" and "sabiduria."
Another place you can find new words in Spanish is in menus at restaurants. The meal itself is a mystery, because you don't yet know what the words mean. When you order the food, then you know what the words or phrases meant to say. You can also ask the waiter or waitress to explain the words in the menu. That is a great way to immerse yourself in the language.
Mystery words, then, are something you can always look at when you are anywhere on the globe. I want to look at travel magazines in Spanish or any other magazines in Spanish. They would be chock full of new mystery words also.
I hope I have piqued your interest in finding mystery words to solve. You get to be a detective and solve a whole lot of cases this way. Remember every new word is a mystery