Wim allready mentioned the Beemster, this polder is on the UNESCO world heritage list. If you visit the small town of Middenbeemster by the end of march you will not see any tourists. Middenbeemster was founded by rich traders from Amsterdam as a place to spend there time of in the country. If you stop by Het Heerenhuis ("The Mansion") you can have a real good dinner, it is recomended by Michelin with a Bib Gourmand. (I will be celebrating my mariage there later on this year.
). Close to this are other real nice places to visit: Alkmaar with the traditional Kaasmarkt (cheese market), Hoorn a town from the Golden Age, Volendam & Monickendam a must see for anyone visiting Holland, Broek in Waterland, one of my personal favourites, Zaanse Schans, you'll find tourists here all year. Vistiting all these places is a +/- 100 km drive, if you want good lighting on each spot you have to come back several mornings/evenings.