herd of polish konik horses at monument where mass grave with horses dating to 16th or 17th century was found

animal brown concept countryside dutch ecology ecosystem environment equine europe fauna field foal grass grassland gray graze grazing green herbivore herd holland horse konik landscape lawn livestock mammal mare meadow national park nature outdoor pasture plain pony prairie protection reserve rural spring stallion standing valley wild wilderness wildlife polish horses monument mass grave dating 16th 17th century found borgharen maasvallei day south limburg netherlands