Romantic weekend jaunts near Berlin

I'm looking to surprise my partner with a romantic weekend in August somewhere within a couple of hours of Berlin by train. Any recommendations?

I'm interested in all types, but if they accept dogs, that's even better.

I was just in Stettin/Szczecin for the day yesterday and I found it positively enchanting!

Spreewald

Prague

might find some ideas here:

Interesting and non-standard day trips from Berlin, Suggested towns and other sights to go visit

Interesting and non-standard day trips from Berlin

You have got to be kidding, it's a dump! Poznan (in Poland) is quite nice but may be a bit of a trek, Schwerin has a nice Schloss but is otherwise unremarkable

yea, szczecin is the real thing
in some streets it looks like berlin 1990

Hamburg! do the touristy stuff if you havent already!