Islands

Walking in a winter wonderland, I found some islands. The first one is above the 3rd windmill(above the waterfall). You can walk on the ice, so walk up past the dock and you will find a dropspot. The other one is to the right of Angelo's house; walk on the ice to get to an island with a tree. Also, does anyone know if you can get items by jumping in the water in the horse track? Please comment if you know! Happy Late Harvest Festival!