In Czech known as Letenské sady, this park offers great views over the city, especially its Old Town. The best place to enjoy the views is from Hanavský Pavilion, a Neo-Baroque structure housing a restaurant. Come here and enjoy the park's open-air beer garden as well as the Europe's oldest carousel, constructed in 1892.
Wikipedia https://en.wikipedia.org/wiki/Letná_Park
More information http://www.prague.eu/en/object/places/488/letna-parks-letenske-sady
Address Letenské sady, 170 00 Prague 7, Czech Republic
Coordinates 50°5'45.658" N 14°25'5.331" E