Museo del Prado Virtual Visit

Proof that a virtual visit can be about the art rather than the corridors. The Prado's online tour of its collection includes 89 works digitized at gigapixel resolution, five of them sculptures captured in 3D, so you can walk the rooms and then zoom into a painting far closer than any gallery barrier allows. That depth matters most with the Spanish and Flemish masters whose detail rewards patience: crowded panels and dense brushwork that blur together in person turn into separate, legible passages on screen. It is the best answer on this list to the clumsy-panorama problem, because the walk-through is only the way in.