The small yet beautiful mansion is the main highlight of this nice park. It is surrounded by water and nowadays hosts many public events.
Wikipedia (German) http://de.wikipedia.org/wiki/Holzhausenpark
Official website of the Mansion http://www.holzhausenschloesschen.de/
Address (Unnamed Road), Frankfurt am Main 60322, Germany
Coordinates 50°7'34.488" N 8°40'41.262" E