Apparently cucumbers have been grown here since the 6th century. They are everywhere; in tasting vats, in jars to take home, in soups, in museums and cheeky ceramic versions on every table. Spreewald is about an hour by train from Berlin, get off at Lubbenau station. Once there the best way to explore is with a kayak or canoe. I hired a kayak for a three hour tour from Richter kayak hire. They kindly gave me a waterproof map with a recommended route. It was super relaxing paddling along the tranquil canals to historic Lehde for a refreshment stop before returning. I think I saw a fish eagle but the otters were elusive. You will definitely encounter mosquitoes so apply insect repellent before you start, that's biodiversity for you. Once back on dry land a beer and gherkin flavored sausage is recommended before catching the train back to Berlin.