There is/are

Presence or absence of a subject in the certain place. There is/are.

There is Buckingham Palace in London.

There are a lot of parks in London.

There are not any palaces in my city.

When we ask about presence or absence of a subject, we put a verb to be on the first place.

Is there a castle in your city?

Yes, there is. No, there isn't.

There is an ancient castle in my city. There is no castle in my city.

Are there any cafes there?

Yes, there are. No, there aren't

There are some cafes there. There aren't any cafes there.