The line of 10 degrees north latitude crosses over a large number of countries, not just four. Here are a few:

* Africa: Senegal, Mali, Burkina Faso, Niger, Chad, Sudan, Eritrea, Djibouti, Somalia

* Asia: India, Myanmar, Thailand, Malaysia, Indonesia, Philippines

* North America: Mexico

* Central America: Nicaragua, Costa Rica, Panama

* South America: Colombia, Venezuela, Guyana, Suriname, French Guiana, Brazil

This is not an exhaustive list, as the line also crosses over various islands and territories in the Atlantic and Pacific Oceans.