The summer home of Frederick Vanderbuilt, scion of the American railroad dynasty founded by his grandfather, Cornelius.
No trust fund kid, old Frederick, he ran the NY Central Railroad for 61 years!! (I thought I'm doing well as an engineer
for 49 years with IBM. I will definitely not try to better his longevity!)
The estate is now a national historic site run by the Parks Service.

PS: After patiently posing for Rad and I about 5 minutes, the katydid flew off unharmed... :)