Stromovka is a big park located between Letna and Prague Zoo in Troja. It was founded as hunting grounds for the Emperor and Czech king Rudolf II. Stromovka is a great place to visit in summer and autumn. It has ponds, cafes, a restaurant and a playground for kids.
In spring there is an amusement park opened nearby called Matejska Pout. Another thing to do in Prague close to Stromovka is visiting Vystaviste Holesovice, which is an exhibition palace built in 1891 in Art Nouveau style. Next to it is Prague Lapidarium where you can see among other things some of the original Charles Bridge statues.