Geographical names with and without the

Do you need the definite article “the” before these place names?

Fill the blank with the definite article “The” before these place names or leave blank?

1. Europe.

2. Himalayas

3. River Danube

4. Asia

5. Alps

6. Spain

7.  Panama Canal

8. Pacific Ocean

9. Northern Ireland

10. Black Sea

11. Atlantic Ocean

12. Irish Republic

13. Bahamas

14. Mount Etna