On dreary days like these when it's slushy outside, I regret the decision to live in a house without a great big bath. ( I'm not declaring myself unhygienic - I do have a shower.)

There's nothing like a long soak in a deep tub to set the world straight - keep you cosy, relax the muscles, melt away anxiety. I find bathtubs great places for meditation, because I never could get the hang of sitting still on a yoga mat. And I have yet to find a better place to read a book - the paper kind.

My predilection for lovely, warm baths, preferably with fragrant foam and lashings of bath salts, is satisfied by the number of hotel rooms I get to stay in that do have excellent bathing facilities.

I'm always miffed to arrive in a room and find there's nowhere to soak myself, especially after a long flight. Happily, it doesn't happen often. While there's a troubling trend in urban hotels to remove the bathtub in favour of the more water-efficient shower stall, five-star hotels, which must include a bath to qualify for their stars, are going all-out in the bathroom stakes, creating increasingly opulent bathing experiences as a point of difference to their competitors.

Baths once were private places for ablutions, but now they're set in panoramic windows, with heartstopping views of, say, London from The Shard (Shangri-La.) There are baths in tree houses (Lion Sands Reserve, South Africa) or inside an aquarium (Atlantis, The Palm, Dubai). There's even a disco-themed black bathtub set in dazzling white-gold tiles in the Freddie Mercury Suite at Eden Roc, St Barths.

Right now, I'm dreaming of my favourite hotel baths and doing my best to transport myself into some of them. The bigger the better as far as I'm concerned, although I don't like to feel marooned.

One of the best I've ever splashed around in is the enormous freestanding tub hewn out of a single piece of stone at Alila Jabal Akhdar, high in the mountains behind Muscat, Oman. It was the size of barge, with splendid views of rocky vistas. The indoor/outdoor bathtub thing is very big now, so the floor-to-ceiling glass doors could be opened to take in the scented Arabic air. The bath could have fitted into it a passing family of goatherds, but it was so beautifully curved it was as comfortable as a baby's cradle.

Each of the baths in the Cafe Royal Hotel in London were carved in situ by Italian craftsmen out of an enormous chunk of Carrera marble, which must have been a logistic and economic nightmare. The bathrooms feel a bit monastic, but when I was floating majestically in the tub I didn't fail to appreciate the effort made on my behalf.

My bathtubs don't have to be architectural masterpieces. I love an old-fashioned claw-footed tub too. A few weeks ago, in Belfast's Merchant Hotel, I had a very nice soak in one after a day spent mucking around in Game of Thrones costumes in the driving rain. (More of this another time.)

I've soaked in picture windows from Guangzhou (The Mandarin Oriental) to the Maldives (Huvafen Fushi). Baths-with-a-view that stand out include the freestanding tubs overlooking the Opera House at Sydney's Four Seasons and the bath in the Japanese Suite of the Peace Hotel in Shanghai, with its view of the Bund and Pudong. And it's hard to beat the sparkling views of the Whitsundays from the tubs at Qualia on Hamilton Island.

I have luxuriated in glass-bottomed bathtubs (Six Senses Laamu, Maldives), copper bathtubs (Monteverdi, Tuscany) and bathtubs filled with rose petals (Ayana, Bali). I've even bathed in a bathtub that may have once contained George Clooney and Robert De Niro, but probably not together (Belmond Cipriani, Venice).

Despite all this sybaritica, however, there's always one thing that irritates me: the lack of a simple bath pillow. It's extraordinary how much trouble hotels go to carve bathtubs out of precious gemstones or whatever and then leave me floundering, searching for something suitable, like a rolled up towel, to put behind my head.

Full marks, then, to the PuLi hotel in Shanghai, which provided my latest hotel bathtub. Not only did I have a view of the city skyline but a long rolled pillow on which to place my jetlagged head.

Bliss.