This is the 5th most frequent Czech word.
to
The Czech word "to" means "it," "this," or "that" in English, depending on context.
Here, 'to' functions as a demonstrative pronoun, substituting for the surprising event or fact.
To mě opravdu překvapilo.
That really surprised me.
In this case, 'to' is a pronoun meaning 'it', referring to the location being talked about.
Chci vědět, kde to je.
I want to know where it is.
In this sentence, 'to' is used as a pronoun meaning 'those' or 'these', referring to the mountains.