Evening! Have just been invited to a wedding in Berlin in July and am very excited. Am thinking of flying to somewhere nearby and taking a few days either side but no idea where to start 
Will be me and DH and 3.5 yo DD and nearly 1 yo DS.
Needs to be cheap also - have just looked at getting ferry to Rotterdam and driving but was super expensive.
Any suggestions for places to stay/go/see much appreciated :)