Queen of the castle: Ruby Wax lives it up in Bavaria

Forget the United Nations – world peace is only a massage away at the Schloss Elmau Luxury Spa and Cultural Hideaway in Bavaria

I've always dreamt of seeing Mad King Ludwig II's castle in Bavaria: a car crash of kitsch and fantasia built high on a precipice above a small German village. Disney himself was inspired by it and stole the idea for his magic kingdom. Ludwig named his version Neuschwanstein and every inch of the interior is apparently filled with paintings and tapestries based on tales of chivalry and scenes from Wagnerian operas, all in a florid Romanesque style. Someone told me he had a grotto built in the bowels of his Schloss which was filled with water so he could float about on his swan boat listening to a live full orchestra while he swigged wine and puffed opium. Clearly he did not make a great king – but what a decorator!

So imagine my surprise when I got to Bavaria and discovered that the place at which I was staying – the Schloss Elmau Luxury Spa and Cultural Hideaway – surely upstaged Ludwig's crib by light years. It has not one but four separate spas inside, four pools and six restaurants (one of them Michelin starred). It also has the largest hotel bookshop in the world, which promises to get any book you want within 24 hours. If you prefer to get active, there's a toboggan run, 70 different hiking trails, two ice rinks, three nearby ski areas, tennis courts, streams, lakes and its own sun. (I made that last bit up.)

After you weave through hilly meadows of purple flowers and tall green pines up a long driveway you come to a white castle. Long, decorative infinity pools reflecting the turrets lead you to the entrance, where men dressed as the footmen from Cinderella rip open the castle doors. This is more like a royal palace than a resort: blazing fireplaces, long cream silk curtains, modern red-gold wall fixtures (partly for light, partly art) and glass cabinets filled with French patisseries. These aren't your normal bun-and-cream collisions but exquisite sculptures that should be in the Louvre, not in your mouth. Most of the walls are floor-to-ceiling windows, where you look out at the snow-capped Wetterstein mountains. When we first arrived we just saw rolling hills of giant pine and birch, then the clouds blew away and, as my daughter said, "Boom, it was Everest." It's as if God had commanded: "Don't give them too much at once."

Bavaria must be incredibly temperamental. On the first day it was a warm spring day with a light breeze; on the second I woke up to full-fat snow, the entire landscape sugar-coated and dripping in icicles while the sun was blazing. I still don't know if the effect was something the hotel put on just for us.

The first time we went to breakfast I had a moment of terror when we arrived at a large glass-walled dining hall filled to the brim with very blonde, very pale, tiny German children. The parents each had about five to 10 offspring in varying sizes, all the way down to a pudgy pink-cheeked bald baby. I felt like I was at auditions for The Sound of Music.

Each mother was stick-thin, coated in casual couture that subtly showed off her jewels, her fur boots and her fertility. How they remained so straw-like after 10 babies I do not know; maybe they give birth through their knees. The husbands, on the other hand, had mostly gone to fat. They sat like big butterballs, all gold hair and red cheeks, and sported those Alpine trilbies with pheasant feathers sticking out.

Luckily, it turned out that after breakfast I never saw any of those children again, such are the dimensions of Schloss Elmau. There is apparently a wing just for the little ones, where they have their own indoor pool, their own massage therapists, a Finnish sauna, steam room and a small "laconium", whatever that is. They have teachers on tap, their own literary festivals, their own ski guides – plus beauty treatments for teenagers. You need never see your kids again.

But I never saw the children's wing. In fact, I never saw most of what was offered at the Schloss because there are three floors containing 3,000 metres of walkways that lead from one spa to the next. I should have left breadcrumbs to find my way through the paths; the most strenuous exercise I managed during my stay was looking for the lobby.

I did find the Badehaus Spa, which alone would rank as the greatest spa I've ever seen – yet here at the Schloss there are three more. In the Badehaus you pass through a warm wooden room where you can lounge and read magazines while ingesting dates, nuts and herbal teas. This room leads to a blue-lit black-tiled steam room and a Swedish sauna which changes colour every few minutes. Outside is an Olympic-length saltwater pool, freshly fed from a nearby brook which stays hot as you swim among the snowflakes. Above the salt pool two storeys up is another hot pool that snakes its way around the side of the Schloss. Don't ask me how they got it up there. It makes Mad King Ludwig's castle floor plans look sane.

If you can still walk after all that, you could try to find the treatment rooms. Here you can get pretty much what's available anywhere in the world: Thai, Balinese, Lomi Lomi, Nui Hawaiian, Vunkuwa African, Chinese Yin Yang and Ayurvedic massage are all on offer.

There's a separate Turkish hammam that also has its own wing. Here there are three large domed rooms with elaborate pillars, arched ceilings and fountains. You're served tea and Turkish sweets as you lie on cushions and sofas in what could be a five-star harem. You start off in your choice of stream rooms, which will depend on what you want to inhale: menthol or eucalyptus, it's your choice. When I came out, a tellak (which means "Master of the Hamam") called Sahid asked me to lie on a platform and began by giving me a peel all over my body, using an exfoliation glove to remove the dead skin. Afterwards he delicately washed me. I tried to shut down my brain (Sahid was very good looking, wearing only a scarf wrapped around his waist).

After a while it felt as if he was washing a child, with me being the child. I'd been expecting more of an Arabian Nights vibe and it ended up more like me aged two with mummy in the tub. I loved it; my limbs just surrendered to the pro on the marble slab. I was almost moved to tears: my mother was never this good; she'd always drop me.

Then it got surreal. Sahid dipped something long, ropey and white into a soapy bucket brought it up to his mouth and blew into it. The wet rope suddenly expanded into a gigantic wet balloon, and when he ran his hand down it, a mountain of bubbles squeezed out on top of me. So there I was, a baby under a giant mountain of bubbles with this beautiful man blowing up linen bags and loading on more and more suds.

I didn't know whether to laugh or write poetry, but it was one of those rare times in life where I really had no words; small talk just wasn't appropriate. I couldn't exactly say, "Have you been blowing bags of bubbles on people for a long time?"

Finally he took a golden bowl and rinsed me like I was some kind of expensive rare fish. This all does wonders for your self-esteem – and you will probably never be so clean again in your life.

It was also an unexpected change from your average English spa treatment, which usually involves a therapist in a pink gown speaking in a tiny vegetarian voice while applying moisturiser with about the same pressure as a mosquito landing. She then tells you she's draining your lymph nodes and asks you to drink lots of water when she's finished... as if your body even knew she was there.

By now I was crawling through the tunnels on all fours in liquid form. I could scarcely make it out the door, but there was an outside spa with its own pool among the trees and a sauna on the river where people jumped straight into icy waterfalls. And if you don't feel like moving a muscle you can crawl to the concert hall, where twice a week there's live jazz, classical, or chamber music.

Every night we went to another restaurant – each better than the last. Fondue was the speciality at The Kaminstüberl, which had an intimate Swiss chalet atmosphere. The Fidelio was a very plush Italian restaurant filled with bay trees, lit up with red lights and waterfalls of silk curtains to divide the areas. I loved the Winter Garten, which had spectacular views and a terrace with rooms off to the sides where you could listen to maestros practicing on their grand pianos for the evening concerts. I ate something here that redefined what sirloin beef and vegetables should taste like. I very rarely pay attention to what's in my mouth – I mostly go for quantity rather than quality – but this time I was caught short. It was a euphoric taste orgy. It all made sense when I was told their kitchen was the same used for the Schloss's Michelin-starred restaurant Luce D'oro.

I had heard talk that the owner and architectural visionary behind the place, Dietmar Müller-Elmau, was a genius. I met him on day three and there was no question: the description was on the button. He told me the history of the house. His grandfather, Dr Johannes Müller, borrowed money from a countess so he could buy the property and build Schloss Elmau. Dr Müller was apparently a philosopher who believed that in order to free ourselves from ourselves, we have to merge ourselves with the universe. In other words, we need to become free of our "I". God knows what's left when you get rid of your "I", but that's what he believed. He didn't actually give any instructions on how to do this, but he brought in the world's greatest musicians and told his guests if they immersed themselves in the music they could forget about their "I"s. This really didn't work but they had a great time anyway.

The place went to ruin until Müller-Elmau, a graduate of Cornell University, turned out to be a computer whizz and invented a very successful internet-booking service for hotels and restaurants around the world. He called this programme Fidelio and 10 years ago he sold it, clearly making enough to fulfil his fantasy of creating a resort. Luckily, most of the old Schloss burnt down because you just can't go re-doing these places on a whim. He said the fire meant he could "recode the genetics" of the building. I asked if he burnt it down. The answer was "no".

His vision was the opposite of his grandfather's, in that he believed we shouldn't get rid of the "I", we should give the "I" what it wants. His all-new Schloss reflects that concept: whatever you want you can get. Isolation, a family holiday, a romantic get-away, a spiritual experience – they're all under one roof. To feed his mind, which really is remarkable – you can actually hear his synapses firing – Müller-Elmau has set up international conferences. Some of the topics have included "Wagner in the Third Reich" lead by the world's foremost historian of the Holocaust and "Islam through Jewish Eyes" led by Jewish and Muslim scholars. His plan is that he invites people from seemingly opposing sides: Christians, Muslims, Jews, Wagnerians, Americans, whoever, and gives them a platform to debate openly and honestly outside the political arena. No matter how conflicting their beliefs, he says, some of them actually bond when they meet on neutral terrain: the sauna.

If this isn't the greatest idea as a means toward world peace I don't know what is. I mean, how hostile can you be in a spa? Why hasn't the UN thought of this? In a way, I felt I met the contemporary version of King Ludwig – not mad at all, just ahead of his time. He wanted what he wanted no matter the cost, he had a vision and followed it to the end. Just like Ludwig's Castle, Müller-Elmau's Schloss is his masterpiece.

Travel essentials: Bavaria

Getting there

* The closest airport is Innsbruck in Austria, served by easyJet (0905 821 0905; easyJet.com). Munich (90 minutes' drive) is also served by easyJet, Lufthansa (0870 8377 747; lufthansa.com), Bmibaby (0871 224 0224; bmibaby.com) and BA (0844 493 0787; ba.com).

Staying there

* Schloss Elmau Spa & Cultural Hideaway, Oberbayern, Germany (00 49 8823 180; schloss-elmau.de). Doubles from €200.

More information

* visitbavaria.com; 00 49 8323 802 550