Time in Berlin: 4 nights/ 3 full days and one half day

No, you will have to prioritize.

Berlin is huge and has extremely many sights and attractions. 3 days are an (over)-tough schedule if you want to press Potsdam and Oranienburg into it, means for Berlin itself you will have less than 1.5 days.

Possible to see in one day?

If a half day means really full 12 hours you could visit Potsdam, so normally plan a full day.

Memorial Sachsenhausen is one area so 4-6 hours including S-Bahn ride. But be aware that a visit to Sachsenhausen is not a touristic funny-bunny rush through. Maybe you want to spend rest of day in peace and not with other sights.

Also Wannsee you can spend easily a full day, minimum half day - depending on what you plan to do there.

Still to se the other Berlin sights

Just look at top 10 list of VisitBerlin. With reamining 1.5 days or even only 1 day you can see few of them from outside and maybe 1 museum for 2 hours from inside. But you will still miss some sights and worth-visiting areas listed in the 3-day itinerary of VisitBerlin.

Tip: make yourself familiar with Berlin's public transport - and do not forget to time stamp tickets.

Sorry, just an honest answer.

Maybe Wannsee and Potsdam since they are in the same direction. Wannsee and Oranienburg (where the camp memorial is) are in different directions.

I would suggest getting out to Wannsee early, be there when it opens. Then by 13:00 hrs take train to Potsdam Hbf. , get on one of the guided bus tours that includes both Neues Palais and Sans Souci outside of Potsdam Hbf. You'll see them immediatley upon getting off the train and exiting the station. The Tourist Office is on the top floor of Potsdam Hbf as is the Reisezentrum.

The next day take the regional train from Berlin Hbf to Oranienburg, the terminus is Stralsund. Or, you can inquire about a tour going there at the Berlin Tourist Office, one is in Berlin Hbf, another one is at the Brandenburg Gate, just east of the columns before Pariser Platz.

Ty. Only want honest answers, other wise what would be the point. I should have mentioned in regard to Sachsenhausen that I will have visited Dachau the week before, so would I "need" to see another camp if I need to prioritize my limited time? I know each place is different

One concentration camp is enough imo. Dachau and Eicke's organization were the prototype and school for the other concentration camps, also Sachsenhausen. A different category of contempt against humanity were the extermination camps.

If by "Wannsee" you meant the "House of the Wannsee Conference" (by far not the only thing you can do in Wannsee) I would opt that out as well. Reason: the Wannsee Conference was not a decider meeting - so still a tragody that it happened but at the end just an operations meeting, not the final decision about industrial organized Holocaust which was done before.

Info: the today's memorial site was a youth camp in the 70s. We made a 2-day trip with Kindergarten (within West-Berlin). So, I was playing, eating and sleeping in that house and its rooms for two nights during my childhood. As young kids in age 4 and 5 we had a good time there.

Ty for that very informative response. Are you saying then only do the Potsdam visit, not Wannsee not Sachsen?

MarkK, our resident Berliner (and by that, I don't mean jelly doughnut), is absolutely right. There is much to do in Berlin... so much so, that it's hard to figure out what to exclude to get down to a 3.5-day visit.

I will have seen Dachau the week b4, so do u "need" to see another
camp?

I agree with MarkK. One concentration camp is enough. It's easy to turn a trip to Germany into one long slog of depression; don't fall into that trap! Also, don't get too caught up in what others think you "need to see." Your trip will be much more meaningful to you if you build it around your interests. On my first trip to Berlin, it was awesome for me visit the Bonhoeffer House because I've read Dietrich Bonhoeffer's books and biography, but the house should not be on 98-99% of Berlin itineraries. Likewise, I think the Berlin Airlift is one of the US's greatest moments, so a tour of Tempelhof Airport was an important part of my first trip (and also enormously enjoyed by me).

To answer your question, you cannot do all 3 activities in one day. My opinion is that Potsdam alone can fill an entire day, particularly if you are interested in WWII history and want to add on a visit to Cecilienhof, the site of the Potsdam conference at the end of WWII. The meeting room is still set as it was for the conference, and you can visit Truman's and Churchill's (later Attlee's) chambers.

As for filling your time in Berlin, MarkK has given you a great resource -- the Visit Berlin website. The Visit Berlin app is great, too, and is full of "off the beaten track" places to go and restaurant suggestions from locals, though with only 3.5 days to see Berlin, you will probably spend most of your time on the beaten track. RS also gives his opinion of Berlin's "greatest hits" on his Berlin Travel Guide page (expand the "At a Glance" section). The Rough Guide to Berlin is an EXCELLENT resource for Berlin (thanks to Fred, for recommending it to me about 18 months ago).

If you would like to add a little more structure to your visit for a half-day or longer, a tour may be a good idea. Insider Tour gets good reviews on this forum for inexpensive group tours. Context Travel offers more-cerebral, more-expensive small group tours (6 people or less). Robert Sommer offers more pricey private tours, but gives the perspective of someone who grew up in East Berlin during DDR times and who was the 15 yo son of a DDR bureaucrat when the Wall fell. I've used Context and Robert; I can highly recommend both.

Happy planning!

Oh, yeah... Wannsee. The conference center has an excellent exhibition on the Wannsee Conference. I saw it during my first trip to Berlin, but I had 8 days in Berlin. By the time you travel there and view the exhibit, it will take up half a day. You could pair it with a trip to Potsdam as suggested above (and be selective about what you see at Potsdam) OR you could do it on a separate day. Whether it's "worth it" is highly dependent on your priorities and interests.

Info: Berliners (Berlin born residents) call Berliner (the doughnut) "Pfannkuchen" which is a completey different food in the rest of Germany :-)

For the history buffs I recommend the berlinHistory app.

As contrast to the Nazi view you could visit Silent Heroes and German Resistance Memorial Center.

If you are deciding between Dachau and Sachenhausen, they have one aspect in common historically, both were set up in 1933 and were the first constructed concentrations camps (KZ) designed for political opponents. Dachau was especially set up too as the "learning camp" for systematic brutality, a model for camps to be built afterwards.

Read about the reaction of US troops upon reaching the camp in April 1945 and what ensued. It's in Rick Atkinson's 3rd volume of his trilogy of the US Army in WW2 on the war in Europe (ETO).

Of course, I would recommend spending more time in Potsdam, freeing up time for that instead of going to another place, especially if you want more than an overview offered in a tour, depending on your depth of interest in the town apart and away from the Zentrum.

Just walking around away from the Zentrum is worth your time if you want to get an insight into the town and life. Read up on it, know what its reputation was in the course of Prussian history.

If you want to do something quite different, sign up for a river cruise at the Tourist Office , a river cruise on the Havel, and see some of the sights of rural Brandenburg.