TreeAlive maps family trees. When a visitor's ancestors lived in Delaware, the markers standing near those places surface automatically alongside their family's journey:
Block House · a few streets from where a family lived in the 1850s · the 1654 New Sweden blockhouse at Naamans, the only house remaining from the Swedish colony
A marker stops being a roadside plaque and becomes a destination with a personal reason to visit. Open the live demo tree, choose the Crossings tab, and turn on Historical Markers to see the experience working (the demo family’s markers are in Pennsylvania; a Delaware family sees Delaware’s).