What was a factor keeping Europeans out of interior Africa until the elate 1800s?

One major factor keeping Europeans out of interior Africa until the late 1800s was the challenging geography of the continent, including dense rainforests, vast deserts, and formidable river systems that made travel and exploration difficult. Additionally, the presence of tropical diseases, such as malaria and yellow fever, posed significant health risks to European explorers and settlers. These barriers were compounded by limited knowledge of Africa’s interior and strong resistance from local populations. Together, these factors delayed European penetration into the continent until advancements in medicine and technology, along with the rise of colonial interests, facilitated exploration in the late 19th century.