Letná Park is a large park on Letná hill, built on a plateau above steep embankments along the Vltava River in Prague, Czech Republic. Letná's elevation and location afford commanding views of the Prague Old Town.
"Leten", originally called "summer camp" or "place to sunbathe" gained its importance in the Middle Ages, when the first military camps were located there due to their strategic location. The areas were mainly vineyards and gardens. It was not until the end of the 19th century that it began to be systematically colonized. Over time, the plains of this area of the city became a place of meeting, entertainment and recreation.
Wikipedia https://en.wikipedia.org/wiki/Letná_Park
Coordinates 50°5'47.077" N 14°25'39.579" E