This gateway, which divides the first and second courtyard of Prague Castle, was built by Emperor Matthias in the 17th century. Resembling a triumphal arch, this gate was designed by Giovanni Maria Filippi and is believed to be one of the first examples of Baroque style in Bohemia.
Wikipedia https://en.wikipedia.org/wiki/Matthias_Gate
More information http://www.prague.cz/matthias-gate/
Address Pražský hrad, 119 08 Prague 1, Czech Republic
Coordinates 50°5'23.613" N 14°23'55.505" E