Las Vegas has had its share of interesting pools over the years, including the iconic above-ground facility, with its "porthole" windows, at the now-defunct Glass Pool in; the former champagne-glass-shaped pool at the Plaza, which occupied the spot above the entrance that's now home to Oscar's Steakhouse; the cantilevered pool at the Palms' Sky Villa (previously the Playboy Fantasy Suite); and The Tank, the current aquarium-centered pool complex at the Golden Nugget that features a three-story fully-enclosed water slide that zips patrons through the resort's live shark tank. Contemporary offerings also include poolside and swim-up gaming; plenty of both rooftop and topless options; a salt-water facility (at MGM Grand's Wet Republic); and sandy beaches/bottoms (at the Rio, Mandalay Bay, and Green Valley Ranch). There has never, however, been a hotel-casino with an indoor pool, nor any plans for retractable roofs, since until the whole "daylife" scene exploded in recent years, Las Vegas resort-casinos didn't want to encourage their guests to waste too much valuable gambling time lounging on a pool deck and mainly catered to an adult crowd as opposed to families, hence pool facilities tended to be fairly basic and seasonal.
That said, there were once two indoor-outdoor pools, today reduced to just one. The pioneer in this respect, and also home to the city's first swim-up blackjack table, was the Tropicana. Added as part of a major remodel in the mid-'80s, this facility was also the first year-round pool in Las Vegas, since the indoor portion could be separated off during the cold winter months. However, after Aztar sold the 34-acre property to Columbia Sussex Corporation for $2.8 billion back in 2006, a massive remodeling of the property was announced and although not all of the plans were implemented, those relating to the pool area were, over time. This resulted in the demise of the indoor-outdoor facility, which was replaced first by the abortive "Nikki Beach" South Beach-themed affair, and then the equally disastrous "Bagatelle" experiment, before arrangements with third-party management were abandoned in favor of bringing the pool complex back under the direct control of the property.
The other indoor-outdoor facility is to be found at the non-gaming non-smoking Platinum Hotel & Spa, located off the Strip at 211 East Flamingo Road. Guests pass from one side to the other by swimming under a glass semi-wall and, unlike the Trop's old facility, this one is heated year-round and the outside portion never separated off. It's tricky to explain, so here are a couple of interactive views, courtesy of Google Maps, which clearly show the indoor and corresponding outdoor sections.
Other hotels, including Embassy Suites Convention Center (3600 Paradise Road), Baymont Inn & Suites (on Robindale Road, about a mile and a half south of Mandalay Bay), Bluegreen Club 36 (a timeshare on E. Tropicana that rents out rooms to non-owners like a hotel), and some Best Western and La Quinta properties, boast indoor pools, mainly of a fairly modest nature, while Las Vegas is also home to a number of municipal facilities and private athletic clubs with indoor pools, but these are designed, primarily, to cater to the resident population as opposed to tourists.
