Final answer:
The blank is filled with 'Mesoamerica,' a region that includes modern Mexico and parts of Central America, known for its pre-Columbian civilizations such as the Maya and Aztec.
Step-by-step explanation:
The region that includes what is now called Mexico and parts of Central America is known as Mesoamerica. Mesoamerica was home to several pre-Columbian civilizations such as the Maya,
Inca, and Aztecs, and is characterized by its diverse geographic landscape. This region includes central and south Mexico, as well as Belize, Guatemala, and the western portions of Honduras and El Salvador.
Notable for its failure to exploit certain technological innovations such as the wheel or metalworking until 900 CE, Mesoamerica nevertheless developed significant artistic skills including megalithic sculpture and weapons from obsidian.
It is considered the cultural heart because it hosted early human civilizations and developed distinct cultural traits like a complex pantheon, architectural style, a ballgame, and a 260-day calendar.