From Dizzying Skylines to Underwater Grottoes and Blood-Red Water: A Guide to the World’s Most Unusual Swimming Pools

Some travelers like to admire a city from above—preferably while floating in warm water, pretending their inbox doesn’t exist. That’s where panoramic rooftop pools come in. But honestly? That trend is only the first page of the story.

The pool world gets weirder (and better): there are purpose-built training pools for freedivers, “sunken city” dive playgrounds, and even a pool that looks alarmingly red—like someone spilled a thriller into the tiles. I pulled together a guide to the most unusual and beautiful pools across the globe, the kind you remember long after your swimsuit dries.

Marina Bay Sands Infinity Pool — Singapore

At 145 meters (476 feet) long, the famous rooftop pool at Marina Bay Sands feels less like a pool and more like a sleek tropical river, with palms leaning in as if they’re trying to eavesdrop on your vacation. It sits on the 57th floor—about 630 feet above the ground, and the view hits hardest at dusk when Singapore flips on its lights and turns theatrical.

The edge looks like the water is about to spill into the city, but it’s a clever illusion. The overflow channels are set slightly below the rim, so the waterline appears endless. It’s a simple trick, and it works. Too well.

All around are sun loungers and real palms (not the “plastic hotel lobby” kind). The entire rooftop deck is called the SkyPark, and it’s landscaped with roughly 700 shrubs and 200 trees. That oddly specific detail is part of why the place doesn’t feel sterile.

Who can swim: only hotel guests. Who can visit: anyone, via the observation deck around the pool.

Observation deck entry: about $39.

Rooms: from roughly $880 per night.

Two-Level Jungle Pool — Hanging Gardens of Bali (Ubud, Indonesia)

Hanging Gardens of Bali looks like it was designed by someone who got distracted mid-sketch and accidentally created a dream. The hotel has 38 pools, all built with the same principle: don’t fight the landscape—follow it.

Each pool has its own terrace, set at different levels along the hillside. From the villas, you look out at rainforest, nearby hills, or a temple tucked into the green. Every villa has a private outdoor pool and a wooden terrace. It’s the kind of place that quietly erases your sense of time.

Some pools sit so close to the trees that they almost touch the branches. Not exactly practical—but undeniably beautiful.

Villa rates: from about $560 per night.

Glass-Bottom Pool — Holiday Inn Shanghai Pudong Kangqiao (Shanghai, China)

This pool is for people who enjoy a bit of adrenaline with their laps. It’s located on the 24th floor of a four-star hotel, and its defining feature is a transparent glass floor that lets you see the street below while you swim.

At night, when the city lights blur the boundary between sky and horizon, it’s especially striking. The glass is made from high-strength material, but if heights make you uneasy… maybe keep your eyes forward.

The hotel has 390 rooms.

Rooms: from about $70 per night.

Deep Dive Dubai — Dubai, UAE

If you’ve ever wanted to descend into a city underwater, this is your place. Deep Dive Dubai reaches a depth of 60 meters (196 feet) and is widely considered the deepest diving pool in the world. It opened in 2021 and quickly became a global magnet for divers.

Even non-divers can try their first immersion with instructors. The scale alone is impressive: the pool holds about 14 million liters of water—enough to fill six Olympic-size pools.

The interior is styled as a sunken city, complete with submerged streets, vehicles, furnished rooms, and even a billiards table. It’s surreal in the best way.

The water is fully filtered every six hours and maintained at a comfortable 86°F (30°C).

Y-40 “The Deep Joy” — Terme Millepini (Montegrotto Terme, Italy)

Y-40 reaches 42 meters (138 feet) and is designed specifically for deep-water training. Beneath the surface are underwater tunnels, four artificial caves, and purpose-built labyrinths.

The pool is filled with thermal water, kept between 90–93°F (32–34°C), allowing many guests to dive without a wetsuit.

The pool measures 21 × 18 meters—roughly the size of two volleyball courts. It doesn’t sound massive, but the depth changes the experience entirely.

Hotel rooms: typically $115–125 per night. Non-guests can access the pool for a separate fee.

Nemo 33 — Uccle, Belgium

Nemo 33 is less a leisure pool and more a dedicated underwater training environment. It was designed by Belgian diving expert John Beernaerts for amateur divers, professionals, rescue teams, stunt performers, and film crews.

The complex is essentially an underwater mini-city, with rooms, corridors, walls, and caves. Large windows at different depths allow visitors to watch divers from outside.

At depths of 7 and 9 meters, oxygen is supplied to designated zones so divers can remain underwater longer without resurfacing.

Entry: about $32. Watching through the windows is free.

The Blood-Red Pool — The Library (Koh Samui, Thailand)

’s signature pool is tiled in shades of yellow, orange, and deep red, giving the water its striking crimson appearance. The color comes entirely from the tiles, not the water itself.

Some guests find the pool unsettling and skip swimming. Others love it. The surrounding loungers and umbrellas match the red palette exactly—it’s a bold design choice, and the hotel fully commits to it.

Rooms: from about $290–315 per night.

Traveler Tips

• If you want a bird’s-eye view of Singapore but can’t access the rooftop pool, ride the Singapore Flyer instead.
• At Nemo 33, personal diving equipment isn’t allowed—you’ll need to rent gear on site.
• Pool water often dries out your skin. Bring a moisturizer and use it after swimming.
• Choose swimwear made from chlorine-resistant fabrics like polyester or polyamide. Natural fabrics lose shape quickly, except in thermal pools.