When it comes to hotel pools, the indoor variety has long been inferior to their outdoor -- often rooftop -- counterparts. But these days, striking decoration, luxury facilities and stunning settings mean many indoor swimming holes can now challenge even the most glamorous of outdoor pools. So go ahead and take a dip at these luxurious indoor pools. The Water Club at Borgata, Atlantic City This nongaming hotel, which is part of the large Borgata complex in Atlantic City, has three indoor pools (and two more outdoors) so there's really no reason for things to get crowded at any of them. A two-lane lap pool is in the two-floor Immersion spa on the 32nd floor and is set against full-length windows that look out to the Atlantic Ocean, the perfect setup for a water workout. An extremely attractive top-floor pool surrounded by lounge chairs, cabanas and lush foliage expresses a more exotic tropical scene than the property's Jersey Shore location. Rooms from $249/ night. www.theborgata.com Altira Macau On the 16th floor of the tallest building on the island of Taipa is the glamorous indoor infinity pool of the impressively massive gaming complex of Altira Macau. It's easy to see why Forbes once named it one of the best hotel pools in the world: One side faces all of the city with crystal-clear floor-to-ceiling windows. Rooms from $235/ night. www.altiramacau.com Waldorf Astoria Chicago The spa at this hotel is done mostly in a stark white, which only further emphasizes the gorgeous rose-design tile-work at the bottom of the pool, giving bathers the feel of swimming over a bed of roses. The 102,600 individually patterned tiles come from Bisazza, an Italian company renowned for its mosaic tile production. Rooms from $435/night, double occupancy.  www.waldorfastoriachicagohotel.com The Charles Hotel, Munich One of the largest pools in Munich, at The Charles Hotel, is also one of the most beautiful. The entire spa is outfitted with marble mosaic tiles, mostly in subdued color1s punctuated with red flourishes. At the pool itself, a very pretty mosaic of red coral shows respect to the 19th century Bavarian royalty, the Wittelsbach family, known for its collection of red coral paraphernalia, from dining cups to jewelry. Rooms from $375/ night, double occupancy. www.roccofortehotels.com If you want to spend the least at one of the spa with one of your close friends,   _   is the most suitable.
The Water Club at Borgata, Atlantic City Altira Macau Waldorf Astoria Chicago The Charles Hotel, Munich