Follow the signs from Amsterdam to Haarlem and Zandvoort. Follow the Zandvoortselaan to Zandvoort. When you arrive in Zandvoort at Haarlemmerstraat just follow the road (on your right site you'll pass a church). You will drive on the Hogeweg till the roudabout. Take the third road directly to the old Water Tower. You'll find the Schelvis Apartments after 50 meters on your right.