Going back all the way to 1837, the Eierhäuschen started essentially as a chicken coop where they sold hard boiled eggs (hence the name). 186 years later, and after being closed for 30 years, the Biergarten, “Anleger zum Eierhäuschen”, part one of the restoration, is already open. This is truly a special place. Full of history, next to the water, inside the Spreepark -- you can bask in the sun and eat some way above average Bratwurst, Fischbrötchen, fresh salads, crispy potatoes and of course, drink beer. Bonus for parents, there's a great playground and ice cream from Paletas. More to come in November. 
Kiehnwerderallee 2, daily from 12 -20 (but check their Insta to make sure)