In a former potato field in Water Mill, New York, the endless roof of what appears to be a horse barn the size of an aircraft hangar recently emerged. It’s the new Parrish Art Museum, designed by Herzog & de Meuron and set to open this November. But for now it’s still beach weather, so the Inquisitive Guest set off for the museum’s Midsummer Party, held for the last time at the original, venerable brick outpost in Southampton. As guests there cooed about the opening of the new digs, which at 34,000 square feet will have triple the exhibition space, we asked what other museums around the globe appeal to their sophisticated sensibilities.