Articles with Geographical Names

We generally use either 'the' or 'no article' with geographical names in English. There isn't a lot of logic! We just need to learn if we need 'the' or 'no article' for each kind of place.

We use 'no article' with:

• Lakes: We visited Lake Geneva.
• Mountains: I saw Mount Fuji from the aeroplane.
• Continents: She loves living in Asia.
• Most countries: She travelled to Chile last year. (But: The USA / the United States, the Netherlands, the Philippines, the United Kingdom / the UK.)
• Counties, states, provinces, regions: They live in California.
• Cities, towns, villages: He stayed in Paris for a week last year.
• Islands: Bali is popular with Australian tourists.

We use 'the' with:

• Rivers: The River Nile flows through Egypt.
• Mountain ranges: We ski in the Alps every year.
• Deserts: She travelled across the Sahara.
• Oceans and seas: We sailed around the Mediterranean.
• Groups of islands: They went to the Canary Islands.

https://www.perfect-english-grammar.com/articles-with-geographical-names.html