When I was in Amsterdam last November I made it a must-do to visit the Cat Boat situated on one of the numerous canals - at first it looked like there are about half a dozen cats but slowly realised they are hidden in all the nooks and crannies :) Its a unique sanctuary, and you can help out either by donation or buying little things there like postcards and badges. You can even buy them online, here is a link which you can explore and learn more: Poezenboot Amsterdam.
It seems apt to post this on the day that we've found home for our kittens. To explain: I live and work on an island with one tomcat and two female cats, one of which is very tame and the other quite feral (mostly because people are not nice to her). The tame one called Gigi keeps having kittens but the guys here refuse to get the male neutered :/ Gigi had five kittens last month, and we have been trying (two women here) to find them a home. Today was lucky! Here they are ready to travel to land :)
GOOD LUCK CUTIES!!