If you like nature, the Swiss Saxony National Park, on the border with the Czech Republic, has great hiking.

https://www.saechsische-schweiz.de/en/

Dresden? Any interest?

Szczecin just across the Polish border. Highly recommend!

Lubben and the Spreewald.
Potsdam.

Anonymous wrote:

Anonymous wrote:Prague.

Too far and Prague is worthy of way more than a few hours.

It's about 4 hours, just a bit beyond the 3.5 cited by OP. It makes a good quick overnight from Berlin. OP should consider it.

Visiting the Sachsenhausen Concentration Camp Memorial was very powerful. Short train ride and 20 minute walk from the station.

Anonymous wrote:On 2 trips to Berlin I’ve gone to Lake Wannsea. It’s about 45 minutes by train. Here’s some info
https://www.tripadvisor.com/Attractions-g187323-Activities-zfn15620481-Berlin.html

Do this, OP! All the other suggestions are more city-oriented than nature.

On 2 trips to Berlin I’ve gone to Lake Wannsea. It’s about 45 minutes by train. Here’s some info
https://www.tripadvisor.com/Attractions-g187323-Activities-zfn15620481-Berlin.html

Potsdam is a nice day trip and very close.

Another nice option is Meissen, visit Meissen factory, castle, enjoy the views.

Go to Hamburg!

Lutherstadt-Wittemburg.

Anonymous wrote:Prague.

Too far and Prague is worthy of way more than a few hours.

The zoo in Leipzig (a 10 minute walk from the station) is truly amazing. Seriously. I was there ten days ago with my family. I would have enjoyed it, even without my 8yo. Highly highly recommend. Leipzig itself is nice too, although not as nice as Dresden (another option for a day trip).

Prague.

I'm traveling to Berlin this fall and will have a day or possibly two where I'd like to venture outside the city. My only stipulation is that it needs to be accessible by train. I'd say 3.5 hrs each way would be my limit. I don't mind waking up early and arriving back in Berlin late , but want to be able to enjoy the excursion and not feel rushed. I'm open to anything but I'm more the type that likes to wander around and look at landscapes/nature vs buildings. I love small village type feels. I'm already venturing to Potsdam one day as it's only 30 min outside the city.