Prague is unusually steep, and the walk up is the price of every good view in the city.

Petřín is the hill on the castle side: a funicular runs up it, there is a lookout tower at the top, and the rose garden below it is free and largely empty compared with anything across the river. Letná, on the opposite bank, gives the view along the bridges that most photographs of Prague are taken from — and has a beer garden attached to it.

Stromovka is the large flat park to the north, and the Vltava islands in the centre are small, free and the easiest escape from the crowd on the bridge.

Articles here cover which green space is actually reachable on foot, what the funicular costs, and where the views are worth the climb.