Closer than Europe
Least distance to travel from the Washington DC area for something that is exotic culturally and in terms of landscape. The only other place that gets close to being culturally exotic this close to DC is Quebec. Of the top I don’t know of any other place with the same exotic landscape close by in DC– it’s deciduous forests and suburbia for as far as you can drive for 100s of miles all around.
Icelandic has thorns, the enigmatic “tl” and a crap load of noun and verb endings.
Slow & Quiet
A good vacation is the reverse of your normal routine. So if you normal routine is information overload and using computers–vacation should be quiet, slow and devoid of extra input.