It's my first visit to Prague. This place is called "Staromestska namesti", right in the old city center.
It's really nice city for a holiday trip. Very Chip (average bill five times cheaper then in London), Nice sightseeng of old Europe city, and even you can go skiing - it is about 120 km from Prague so you can take a bus there from "Cherniy most" subway station in the morning and go back in the evening.