landlocked
adj.adj. describing a country or place that is completely surrounded by land and has no direct access to the ocean. You use this to talk about places that must travel through other countries to reach the sea.
adj. situated entirely within a landmass and having no direct access to an ocean or sea. Often used to describe the geographical constraints of a nation's trade and transport.
Bolivia is a landlocked country in South America.
Because it is a landlocked nation, the government invested heavily in rail infrastructure to facilitate international trade.
The economic development of many landlocked states is significantly hindered by the high tariffs and transit costs imposed by the coastal nations they must pass through to reach global markets.
From land + locked (i.e. "locked-in by land on all sides").