Costa Rica, officially the Republic of Costa Rica, is a country in the Central American region of North America. Costa Rica is bordered by Nicaragua to the north, the Caribbean Sea to the northeast, Panama to the southeast, and the Pacific Ocean to the southwest, as well as maritime border with Ecuador to the south of Cocos Island. It has a population of around five million in a land area of 51,060 km2 (19,710 sq mi). An estimated 333,980 people live in the capital and largest city, San José, with around two million people in the surrounding metropolitan area.

Nicaragua, officially the Republic of Nicaragua, is the geographically largest country in Central America, comprising 130,370 km2 (50,340 sq mi). With a population of 6,850,540 as of 2021, it is the third-most populous country in Central America after Guatemala and Honduras. Nicaragua is bordered by Honduras to the north, the Caribbean Sea to the east, Costa Rica to the south, and the Pacific Ocean and a shared maritime border with El Salvador to the west. The country's largest city and national capital is Managua, the fourth-largest city in Central America with a population of 1,055,247 as of 2020. Nicaragua's multiethnic population includes people of mestizo, indigenous, European, and African heritage. The country's most spoken language is Spanish, though indigenous tribes on the Mosquito Coast speak their own languages and English.