Language
Their Language wasn't something weird both in the time and region, it was the Nahuatl, an ancient language used for another culture, the Aztecs. The Nahuatl of this time wasn't the same Nahuatl that the Aztecs talked, because the Toltec culture was the predecessor culture. Also the Toltec culture improved this language.
Architecture
Something weird in their architecture was some representations. For example, they used to represent the Male Dragons as the pillars of the heaven because they believed that Quetzalcoatl (God of the War of this culture) make the pillars of the collapsed heaven with those dragons.