Final answer:
Finland is the country with the cities Espoo, Tampere, Vantaa, and Oulu. It features important academic institutions and has a relatively small population compared to its geographical size.
Step-by-step explanation:
The country that has the cities of Espoo, Tampere, Vantaa, and Oulu is Finland. Finland is known for its educational institutions such as the University of Oulu and the University of Eastern Finland. These universities have departments focused on different areas of study, including the Department of Ecology and the Department of Biology.
Located in Northern Europe, Finland, along with its neighbors Norway, Sweden, and Denmark, forms part of the Nordic countries, a group often associated with Viking heritage. Despite its large geographical size, Finland is not densely populated, with less than six million residents as of a 2017 census.