We don't usually use an article in expressions with bed, work and home.
We also don't normally use an article in expressions with school, university, prison and hospital.
But we usually use 'the' if someone is just visiting the place, and not there as a student/prisoner/patient, etc
-My son has started school now. I went to the school to meet his teacher.
-I went to the prison a lot when I was a social worker.
-I'm at the hospital. My sister has just had a baby.
We don't normally use an article for continents, most countries, cities, towns, lakes, mountains or universities.
Some countries are different. Country names with United have 'the'. There are other countries which are exceptions too.
So, we say:
-the United Arab Emirates, the United Kingdom, the United States of America, the Bahamas, the Gambia
Seas and oceans, mountain ranges and rivers have the:
-the Atlantic, the Pacific, the Mediterranean
-the Andes, the Himalayas, the Alps
-the Nile, the Amazon, the Yangtze
Universities with 'of' in the title also have the:
-the University of Cape Town, the University of Delhi, the University of Tokyo