I don't know about local internet dating site in Netherland, but there is the international site
www.adultfriendfinder.com, with some ads from Dutch girl wanting to meet men ( and also some couples wanting to meet ).
Unfortunately, you need to pay to contact people there ( like many dating site I guess ), and there are not so much Dutch girl ( about 2200 girls now, but lots of profile are out-of-date ). Anyway with some luck you may meet 1 or 2 girls. But beware, some girls seems pissed about foreign guys wanted a quick fuck while on trip ...
Of course, you can also contact girls living near your place. If you are from the States, there are a lot of very hot profile ... :)