Locally known as Hradčany, this area that surrounds the Prague Castle was regarded as an independent borough until 1784. Now, you can enjoy lookouts over the city from the district with a history dating back to the 9th century. The famous St. Vitus cathedral is located here.
You can freely walk around the area. Check the opening hours of individual attractions.
Wikipedia https://en.wikipedia.org/wiki/Hradčany
Official website https://www.hrad.cz/en/prague-castle/prague-castle-tourist-information/visit-of-prague-castle.shtml
Coordinates 50°5'27.803" N 14°23'45.221" E