(CNN) — Year-round swimming weather and a decent poolside fish taco are good enough perks at many hotel pools in and around Los Angeles. Then there are those inspired South Californian oases striving for something even splashier.
Up on the roof, down in the basement, perched on a secluded peninsula, beckoning from a five-star oceanside resort a tad farther down the freeway, here are a half-dozen posh hotel pool experiences well worth the extra plunge.
1. Millennium Biltmore Hotel Los Angeles
For nearly a century, Downtown L.A.'s grand dame of hotels has hosted kings, presidents, the Beatles, nine Oscars ceremonies, and generations of businessmen milking their corporate expense accounts.
Hiding on a quiet floor below the hotel's frescoed, fanfared lobby is the city's best subterranean splash from the past: the Biltmore's 90-year-old, Roman-style swimming pool.
Decked with columns, shiny brass rails, and blue-and-cream Italian faience tilework, the indoor pool was added to the property three years after the hotel opened its doors in 1923 -- and was designed to "recall the days of Pompeii" according to Margaret Leslie Davis's book, "The Los Angeles Biltmore: The Host of the Coast."
It may also recall scenes from "Bugsy" (1991) and "Cocoon" (1985), among other movies filmed here over the years.
Add a co-ed wet steam, dry sauna, Jacuzzi and surrounding fitness room, and guests can feel good about skipping that date with the beach today. Pool guest policy: Pool and facilities for hotel guests only.
2. Mondrian Los Angeles
At this point, one might expect the Sunset Strip's seasoned epicenter of rooftop pool perches to be upstaged by some hot new West Hollywood arrival too young to remember old "Entourage" set pieces or the "Star Trek: Deep Space Nine" wrap party.
The storied-yet-ageless centerpiece of the Mondrian's lofty Outdoor Living Room with its lovely teak deck, mosaic poolside tables, groovy up-tempo house mixes (pumped underwater), perfect LA panoramas and face-lifted Skybar lounge pulsing a few stairs up is still the place to be for the forever young-ish crowd.
The pretty pool itself might seem somewhat small -- if anyone was here to work on their butterfly stroke.
For lounging with a $16 Poolside Spritz in hand, it's resiliently Olympic-sized.
Pool guest policy: Private to hotel guests until 1 p.m. At night, non-hotel guests can bypass the doorman line with a Skybar table reservation.
3. The Standard, Downtown L.A.
About 15 years ago, The Standard (of West Hollywood fame) chose an old Superior Oil Company building in not-exactly-happening-yet Downtown L.A. as the questionable site for its next boutique hipster hotel.
Did the gambit pay off? Join the party up by the rooftop pool and see for yourself:
Red AstroTurf. Waterbed pods. Cushy couches. Fireplace. Dance area. German beer garden. Weekend morning yoga classes. Revolving DJs setting a seamless pool party atmosphere.
And much-improved aerial views of Downtown -- especially from where you're standing.
If there's a cooler pool atop 12 floors of re-imagined concrete and marble in a resuscitated concrete jungle, the beautiful crowd congregating at this one doesn't yet know about it.
Pool guest policy: Open to non-hotel guests by invite or for a fee.
4. Terranea Resort
Hugging the craggy Palos Verdes peninsula on L.A.'s southern tip like a pirated slice of the Mediterranean, the 102-acre Terranea Resort can claim the perfect quartet of oceanfront pools for every type of guest.
Awash with families, the main 5,000-square-foot-Resort Pool area is equipped with a 140-foot Peninsula Plunge water slide and jumping splash pad.
For less crowds, more Zen and the same spectacular ocean views, there's the saltwater Vista Pool and a Spa Pool furnished with private cabanas and fire pits.
Our favorite pool of the bunch here:
The resort's seasonal Cielo Point pool (open May through September, for guests 18-plus years of age) is about as close as a pool gets to the Pacific -- with live music, craft cocktails, more cabanas and quick access to a private cove to sand your toes.
Pool guest policy: Open to resort guests only.
5. SLS at Beverly Hills
Guests won't be doing much diving in the shallows of Altitude -- the chic, dual-pooled roof deck of the SLS Beverly Hills.
Just deep, delicious luxuriating.
At 3.5 feet in depth, the hotel's "plunge" pool is for ambient basking and contented gazing at palm-frond-silhouetted sunsets to a DJ'd indie-pop soundtrack.
The one-foot deep reflection "pool" is for lounging in a waterborne chaise in a Philippe Starck-designed outdoor living area rimmed with giant vases, oversized art frames and assorted whimsical furnishings.
A range of luxury poolside cabanas (from $300 with a $500 food and beverage minimum) earn their price tag with the most buzz-worthy poolside grub in L.A. -- featuring bite-sized delicacies and specialty cocktails from celebrity chef Jose Andres.
Pool guest policy: Pool use is for hotel and spa guests only. In spring and summer, Altitude is open to non-guests after 6 p.m. for music, food and cocktails.
6. The Resort at Pelican Hill, Newport Beach
Yeah, we know. We've crossed a line, literally. Newport Beach is not in Los Angeles.
But one look at the aptly named Coliseum Pool at five-star Pelican Hill and we think you'll agree: What's a quick drive down the 405 Freeway into neighboring Orange County?
Graced with more than a million hand-placed glass mosaic tiles, the resort's 136-foot-diameter, saltwater showpiece is one of the world's largest perfectly circular pools.
Inspired by its ancient Roman namesake, this is likely the world's only pool that would make an emperor consider reincarnation in the O.C.
Guests can up the opulence quotient by reserving a private luxury cabana (from $200 per day) furnished with a Bose music system, flat-screen HDTVs and beverage-stocked mini fridge. Or by mixing their own Sunday brunch Bloody Mary at the bar.
Either way, Caesar should be by shortly.
Pool guest policy: The pool is for registered guests exclusively. Non-guests can dine at the Coliseum Pool & Grill.