It was your typical sharing-economy job.

Classic Portland story, new twist: Fat cats find a new way to make money off a luxury tower while the little people worry about rent. A whole floor at the big new black building on the east end of the Burnside Bridge is dedicated to short-term rentals—you can rent out the whole thing for up to $7,125 a night on Airbnb.

My reporting came with a perk—my editor wanted me to stay there for a night.

The thing about luxury tower stories is you're never really out of the game. Do it once and you're marked. They always come back at you for more.

"They've got a fancy new indoor mineral pool now, and we need you to go back for a dip," my editor says. "Relax a bit. It'll be nice."

So I found myself texting some girlfriends and going for a soak at the brand-new Knot Springs. For $65, I was in a soft-gray metal tub looking out over the Willamette River at Big Pink and the Made in Oregon sign, with the deer wearing his silly red nose.

Thing is, I like real hot springs. The outdoor kind. But the first time I came to Oregon it was for an Outward Bound trip to Mount Jefferson. It rained every day of the nearly three-week trip—unless it snowed. Did I mention it was July?

(Christine Dong)
(Christine Dong)

Urban and inside is just easier and cleaner. There's no rain inside Knot Springs unless you count the mist of the steam room.

(Thomas Teal)
(Thomas Teal)

These springs also offer a dry towel with a Pendleton-style print. There's a Pendleton-print robe too, for venturing outdoors to the terrace garden.

Would-be hotel pool squatters, beware: The springs are through a locked glass door. Inside, verdant fake plants line the ceiling. It's a pristine, spare concrete space, warmed, metaphorically speaking, by the tiny rounds of wood that line one wall. There's also a gigantic dead tree lying felled on the floor. It's a bench or towel rack, depending on your needs. Floor-to-ceiling windows let in stunningly bright light.

(Christine Dong)
(Christine Dong)

Knot Springs soaking is a three-part process, beginning in the "tepidarium," which hovers just below body temperature to relax muscle tension. Then, you move to the "caldarium," a pool at 102 degrees that's spiked with "pore-opening" minerals. Finally, there's a cold plunge into icy water so cold I was looking for the icebergs. You rotate: hot and cold, hot and cold.

(Christine Dong)
(Christine Dong)

I only dipped into the cold once. Instead, I went outside to the terrace to cool down. The bright green chairs rocked gently. The traffic was loud, but the air was bracing.

Knot Springs, 33 NE 3rd Ave., knotsprings.com. 6 am-10 pm Monday-Friday, 8 am-10 pm Saturday-Sunday. Reservations not yet required.