well, i've been a busy bee yesterday, trying to find more interesting shops, boutiques, cafés and restaurants for you - and maybe it wasn't the greatest idea wearing my newly favourite, fleamarket-found heels when doing so. ouch.
then i remembered that little hidden green gem in mitte, the 'alter garnisonsfriedhof', a tiny old cemetery-turned-park. if you're not the kind of person who finds this kind of place creepy by default, you'll discover an idyllic oasis. get a coffee and a sandwich in some of the nearby restaurants or cafés - many do sell out of house - pick a bench and kick off your shoes. bliss.
p.s.: as with most places in berlin, this cemetery has a very complex history. founded in the 18th century and in use until 1947, it spans a wide stretch of german history. if you'd like to find out more about the cemetery's history, there's an exhibition (in german) in the small building at the entrance. some basic info can be read here.
find it on kleine rosenthaler str. 3, 10119 berlin (mitte), open april-sept 7-19h, oct-march 7-16h