You can donate children’s clothes in Cascais at several locations. One option is to drop them off at a charity called Século, which provides clothes to families in need. They have a white container located up the road next to the school on R. Cesário Verde where you can leave your donations.
Additionally, if you’re interested in a community initiative, there’s a group of parents who collect clothes and other supplies for single mothers and their children, particularly Ukrainian refugees. You can contact Olesya, who runs this initiative, to arrange a pick-up or drop-off.
For more details, you can check the charity’s website here: Século Charity.