Questions & Answers about Каково было там?
In this sentence, каково means something like what was it like?
It is close in meaning to как, but the tone is a little different:
- Как было там? = more neutral, everyday How was it there?
- Каково было там? = more literary, thoughtful, or slightly elevated What was it like there?
So a learner can think of каково as a more special form used for asking about the overall nature or experience of something.
Было is the past tense of быть.
It shows that the question is about the past:
- Каково было там? = What was it like there?
- Каково там? = What is it like there? (present)
So было is what makes the sentence past-tense.