There are actually quite a few countries that don't have a seaport! It's a bit of a tricky question because it depends on how you define a "seaport".

Here are some examples of countries that might fit the bill:

* Landlocked countries: These are the most obvious examples. They are entirely surrounded by land and have no access to the sea. Examples include:

* Bolivia

* Botswana

* Central African Republic

* Chad

* Ethiopia

* Hungary

* Laos

* Liechtenstein

* Luxembourg

* Malawi

* Mali

* Mongolia

* Nepal

* Niger

* Paraguay

* Rwanda

* Switzerland

* Uzbekistan

* Zimbabwe

* Countries with limited access: Some countries have limited access to the sea due to geographic constraints or political issues. These countries might have a port, but it might not be truly a seaport (e.g., a port on a river that doesn't have access to the open ocean).

It's important to remember that access to the sea is a major factor in a country's economic development, so countries without access often face unique challenges.