It's flooded right now and seems to be under construction. You can't walk there without rubber boots or getting your feet wet up until your ankles. There's an estonian information sign at the beginning of the wood path, but nothing in english.

via StreetComplete 47.1

"Это место закрыто навсегда "
The place has gone or never existed. This is an auto-generated note from MAPS.ME application: a user reports a POI that is visible on a map (which can be outdated), but cannot be found on the ground.
POI name: Tädi Anni juures
POI types: amenity-cafe
OSM data version: 2020-07-14T11:22:37Z
#mapsme

Doesn't look like a public park. Probably school's territory for physical education.

This lake will most likely get named "Rõngasjärv" based on local news source. Awaiting for Madis Kallas, the regional minister, to approve this name for this lake:

https://www.err.ee/1608955226/nimetu-veekogu-tallinnas-saab-nimeks-rongasjarv