The War of the Pacific, fought between 1879 and 1883, primarily involved which country becoming landlocked?

The War of the Pacific (1879-1883) was a conflict that primarily involved Bolivia and Chile, along with Peru. The war arose over territorial disputes and control of valuable resources in the nitrate-rich areas of the Atacama Desert. Ultimately, Bolivia lost significant territory to Chile, including its coastal region along the Pacific Ocean. As a result of this territorial loss, Bolivia became landlocked, meaning that it no longer had direct access to the ocean. This has had long-lasting effects on Bolivia's trade and naval aspirations.

In contrast, Chile emerged from the war with expanded territory, gaining not only the formerly Bolivian coastal regions but also regions that were part of Peru. Peru, while also involved, did not lose its coastal access entirely, and Argentina was not a combatant in this specific conflict. Overall, the key outcome of the War of the Pacific was the landlocking of Bolivia, making it the focus of this question.