Kramar's Villa is known for being used as the official residence of the Czech Prime Minister since the late 1990s. Named after the first Czechoslovak prime minister, Karel Kramář, the villa is built in Neo-Baroque style. Its architect, Friedrich Ohmann, also added some Art Nouveau features that can be spotted on the facade.
Opened to the public only occasionally.
Wikipedia https://en.wikipedia.org/wiki/Kramář's_Villa
More information at Prague.eu http://www.prague.eu/en/object/places/1144/kramar-villa-kramarova-vila?back=1
Address Gogolova 212/1, 118 00 Prague 1, Czech Republic
Coordinates 50°5'36.128" N 14°24'37.677" E