Yes, THEBES is a Scrabble word!

Letter values in Scrabble US: T 1, H 4, E 1, B 3, E 1, S 1.

Is it a valid word?

THEBES is a valid word in the official Scrabble dictionary (US) and the UK Scrabble Dictionary, but not in Words with Friends (ENABLE).

an ancient Egyptian city on the Nile River that flourished from the 22nd century BC to the 18th century BC; today the archeological remains include many splendid temples and tombs
an ancient Greek city in Boeotia destroyed by Alexander the Great in 336 BC
100 thebe equal 1 pula in Botswana