Pergamon Museum.

The lines for the Museumsinseln museums were very long when I was in Berlin during the summer of 2015. I recommend doing anything other than simply arriving and standing in the entry line.

You need to do the math, but I think it will be very, very hard to make a pass pay if you spend 2 days at one museum. You can buy city-transit day-tickets separately, so don't attach too much value to the transport feature available with some passes. Also, how many transit trips are you going to take if you spend 2 days at one museum? I'm big on museums, too, and I generally do better buying individual tickets.

I had two major issues with the Berlin Welcome Card with Museumsinseln add-on that I purchased in 2015:

• I still had to stand in the ticket lines on Museumsinseln.
• One of the Museumsinseln museums had a special exhibit. Rather than being required to pay the additional fee, I was told that my Welcome Card couldn't be used at all, so I had to pay the full entry fee (regular charge plus exhibition add-on). I was not a happy camper.

If you check the websites of the key museums you want to visit, you'll probably find a clear statement limiting the senior discount to EU citizens if that is the actual policy. I have occasionally been given that discount even though I am from the US, but I'd make my calculations on the basis of the official rule.

One other thing to be aware of is that just about every German museum I went to required me to check my normal-sized purse. Sometimes there's a staffed counter for that purpose; other times, there are coin-fed lockers that take either 1-euro or 2-euro coins. Someone posted here that you get the coin back when you retrieve your belongings, but I wasn't aware of that.

When I was there for 4 days I just got the Berlin Museum Pass as I didn't feel that the Berlin Pass was as cost effective for me. I don't believe there is a senior discount for the Museum Pass but don't know about the Berlin Pass or the Berlin Welcome Card (which I also didn't think was the correct one for me). You need to compare the passes and do some math to see which work better for what you want to do. According to the website, because of the renovation of the Pergamon Altar, there are longer lines for the museum and the passes don't let you skip the line - not sure if that applies to all the passes but it does to the museum pass. They recommend getting a timed entry (free) online to avoid the longest lines.

If you plan to do any walking tours while there I can highly recommend the Original Berlin Walks. I took two of them - one to Potsdam, which I absolutely loved but it does take up a 1/2 day (so worth it), it doesn't include entrance to the palace but you can do that after the actual tour before returning to Berlin; the other tour was Discover Berlin, which was a general overview but very comprehensive. Both of my guides were wonderful, both American expats, and very interesting and entertaining. There is a senior discount off of there normal price and you don't have to be EU citizens for that.