What it means
Means a place way out in the middle of nowhere in New Zealand, proper back-country stuff where the road goes gravel, the houses vanish, and your phone taps out. People use wop-wops for remote rural spots, especially when they're talking about farms, baches, long drives, or getting stuck miles from town.
Usage examples
"We’re heading to Dave’s bach in the wop-wops this weekend, so stock up in town now, there’s no reception and one dairy for miles."
"We are heading to the bach in the wop-wops past Whakatane for the weekend, no signal, no bakery, no nothing, just fishing and a battery radio that picks up two stations."
"The new venue for the wedding is out in the wop-wops near Marlborough, the cousins from Auckland are renting a minivan because no taxi will go that far at midnight."
"We took one wrong turn outside Taupō and ended up proper in the wop-wops with sheep, gravel, and absolutely no bars."
"Her new flatmate grew up in the wop-wops, so a forty-minute drive to get chips doesn’t even register as far to him."
Where it comes from
Sits firmly in New Zealand English, possibly born from a Maori expression, possibly from an onomatopoeic invention of early settlers heading bush. Either way, the wop-wops have meant deep countryside for at least a hundred years, from the back roads of the King Country to the gravel paths up to anyone family bach by the lake.