no absolute "best" place. everyone go for differnt things.
those who want exciting sex, may think that public place is best.
Like some staricase, deserted car park etc. They dun want to be
caught yet they choose a place that they may be caught in
action.
For those nature lovers, they may want to rent a yacht and have sex
under the sun in the middle of the sea. or maybe on the beach
during very late hours when no one is around.
