Photo: User:Aktron, CC BY-SA 3.0 Free parks & gardens in Prague
Photo: User:Aktron, CC BY-SA 3.0 
Photo: Ludek, CC BY-SA 3.0 Petřín Hill
Free outside, paid inside
Photo: Chmee2, CC BY-SA 3.0 Kampa Island
Free, always
Photo: V. Groulík. Original uploader was Martinect at cs.wikipedia, CC BY-SA 3.0 Wallenstein Garden
Free at certain timesFranciscan Garden
Free, alwaysRiegrovy Sady
Free, always
Photo: I would appreciate being notified if you use my work outside Wikimedia. More of my work can be found in my personal gall, CC BY-SA 3.0 Stromovka
Free, alwaysGrébovka
Free, always
Photo: Rémi Diligent, Public domain