WWII highlights and hiking?

I will let others chime in on Berlin, but I would suggest something smaller and closer to the mountains than Munich if you want the great outdoors and hiking. Perhaps somewhere like Garmisch-Partenkirchen.

Berlin is/was a swamp, and it's easy to walk because it's flat. Every hill in Berlin is a pile of rubble from the WWII bombing and subsequent clean up. There are some very interesting underground tours available, and you can always see the major points.

Munich really doesn't have much WWII stuff, most of the history there was prior to the fighting. Still, it's a great city to visit.

What you're going to find is the the majority of the military sites are, for almost all the wars in Europe, places where a major battle was fought within a very specific local, or places where the fighting was somewhat static. Realize that once the Allies passed the Westwall everything moved very quickly, so there's not a lot of "battlefield" from WWII inside the current German borders to the west. There are places of interest, but the main places people trend to are Normandy (France), Bastogne (Belgium), the Rhine bridges (Remagen, Nijmegan, Oosterbruck, etc.), Westwall/Maginot Line, and places such as those. And a lot of the sites that don't get much publicity (St. Vith, Arracourt, Metz, etc.) all of which had major fighting, and where you can still find some memorials and fortifications, are slowly falling to ruin.

If you flew into Amsterdam, headed to Aachen (site of a major battle), Bastogne (likewise), Luxembourg (Patton grave and the WWII Museum), St Avold (the US Cemetery), and then go down the Mosel to Koblenz (really good German Military museum), and then to Frankfurt you'd have a lot to see and two weeks should give you a taste. You could easily throw in Remagen and Metz, and some of the Maginot line forts. Maybe even the Westwall bunker museum in Bad Bergzaben.

"We will have about 2 weeks, can fly in/out of Frankfurt ..."

FRA airport is perfect. 2 weeks is a nice amount of time. You will want more than just hiking and WW II for 2 weeks. I suggest 3 base towns...

1) Near FRA: The Middle Rhine Valley is a good base for hiking, WW II stuff, and for taking in "old-world" Germany.

WW II:
- Remagen's WW II Peace Museum (Watch the "Bridge at Remagen", 60's film, beforehand.)
- Cologne's Documentation Centre
- Irrel (near Trier in the Mosel Valley) has a German bunker site (Panzerwerk Katzenkopf, open Sunday afternoons. Most bunkers were blown up after the war. The handful that are left, including the one KGC mentions in Bad Bergzabern, are managed by locals as a rule and have very limited visiting hours )

Hiking:
There are huge numbers of scenic hiking trails in both the Rhine and Mosel River valleys and neighboring countryside . And of course any visit to Burg Eltz (medieval castle) can include a hike from the town of Moselkern, as can a visit to Marksburg (medieval castle) from Braubach's town center.

• Rhine Castle Trail (cliffside trail through woodlands, pasture) connects west-bank Rhine towns
• Rheinsteig Trail (connects east-bank Rhine towns)
• Dream-trails on the Mosel River

Old-world towns and villages:
- https://www.mittelrheinentdecken.de/en/
- https://www.mosel-inside.de/en/travel-guide/mosel-villages.html

2) Berlin (well covered in all the guidebooks, all kinds of things to see/do.)

3) Nuremberg (WW II plus much more...)

• WW stuff is well covered in all the guidebooks; what's often not covered are the many other things that make Nuremberg interesting and the multiple day trips that are possible from Nuremberg. Desirable day trips by regional train include...

Bamberg
Rothenburg
Würzburg
Regensburg
Bad Windsheim
Iphofen

(Check Tripadvisor for more info on the above places.)

• Nuremberg places of interest: https://tourismus.nuernberg.de/en/discover/museums/ https://tourismus.nuernberg.de/en/discover/places-of-interest/

I suggest you spend your final day/night in/near FRA airport either in Mainz or in Frankfurt.

If you're out for WW2 history in and around Berlin, there is lots of it, depending on your interests to track them down. Do your interests include the others, or just pertaining to Americans? What about the British, Russians, Germans?

I suggest Halbe and Seelow, (the battlefield memorial museum is there) along with Russian armour, tanks, tank destroyers, etc, both places reachable by public transport, especially if you're into the Eastern Front.

There is the British Air Force (RAF) military cemetery in Grunewald on Heerstrasse, plus the British military cemetery in Berlin-Starnsdorf. What about German military cemeteries from WW1 and WW2 located in Potsdam? One is within walking distance from Potsdam Hbf. (Neuer Friedhof)

With the exception of Halbe, I have been to all the other places I am suggesting to you.

If you want to see evidence of German naval history pertaining to WW1 and 2, I suggest going to Kiel Hbf, take the bus from the bus depot with the terminus "Laboe" , the naval memorial and museum is there plus the sub on the beach. I saw it 50 years ago in 1977. More naval history is located in the Museum in Stralsund, a city well worth seeing anyway.

...would like to see some WWII history museums/sights...

Have him check out this site.

thirdreichruins.com

It has many photos taken during or just after the war, and photos of the same places taken in later years. It's possible that you will go to some of the places depicted. If so, the contrast between then and now is very interesting.

I can second the idea to visit Aachen and the Eifel Countryside along the Belgian border. It was the site of the longest battle in Hürtgenwald. 33,000 Amercians became casualties. When I went with my family many years ago there were still remnants in the Hürtgenwald while hiking. And the Dragon's teeth anti tank concrete meant to stop the allied tanks. Not sure if those have since been ripped up. There was a peace museum in Vossenack in the valley.

Hurtgenwald with a guide is a “highlight” for a battle where both sides ground each other down for no real gain on either side. There are local guides there. Seelow Heights east of Berlin was a major battle that also was critical to the Russians. A little further east in what is now Poland are the remains of Luft Stalag 3, the site of the “Great Escape”.

You might also attend an Airshow in Germany. There are a number of real and recreated aircraft from the Luftwaffe on the summer circuit. Finally as others mentioned the U-Boat Memorial at Laboe, an excellent choice.

Tread lightly viewing WWII “highlights” It was total war in Germany and for the wonderful years I spent there, always a thin veil of sadness in an otherwise really great country.

Above it is pointed out that German military memorials, monuments, museums pertaining to WW2 and WW1 , cemeteries are more likely to be located in North Germany and I would add in eastern Germany as well, at least evidence of that I have tracked down, (in addition to those mentioned above), such as in Eutin/Holstein on the grounds of the Schloss, Minden an der Weser, Wünstdorf/Brandenburg, (this was Wünstdorf-Zossen ), Magdeburg, and Spandau.

If you end up with only time to seeing those singular sites in Berlin, there is also the Invaliden Friedhof (cemetery), ca. 40 min. walk from Berlin Hbf., the oldest Prussian-German military cemetery. The Resistance Museum on Stauffenberg Straße is housed in the original building of the General Staff prior to WW1 and the HQ for the Replacement Army (Ersatzarmee) where the plans for 20 July 1944 were devised/hatched. (if you saw the movie).

If you have a rental car, get out to Berlin Krampnitz (not far from Grunewald) , remnants of the tank school and grounds.