Where is it? Just 2½ hours from London, the Welsh capital has a new image: dynamic, forward looking, listed among the world's top destinations for alternative tourism. Arts, culture and sports compete with upmarket shopping, but top prize for regeneration goes to Cardiff Bay, where a new freshwater lake reflects one of the trendiest waterfronts in Europe. Landmarks abound along the shore, none more iconic than the lofty St David's Hotel, poised at the tip of a small peninsula. Rising to seven floors, this glass monument to the glory of Wales opened in 1999, is topped by a roof representing a dragon, with, some say, outstretched wings. Use your imagination and you might see an ocean liner about to set sail, instead.

Fine, but what's on the inside? Top of the list is the Marine Spa, which has a raft of awards to its name. Among the rituals on offer is the wonderfully named Sin and Tonic (which includes a marine algae body wrap and a healthy lunch) while the ultimate treat - for any celebration - has to be the Spa Champagne Afternoon. The indoor pool, meanwhile, is the jewel in the crown, especially the jacuzzi area: lie on submerged "jet loungers" or enjoy being tickled by a stream of bubbles coming up through the floor. Experience, too, the swan-neck fountain; the "walkway" where you battle, chest deep, against the current; the sauna; the gym; and the fabulous views through panoramic windows.

Tell us about the rooms There are 142 of them and they're bright and comfortable, in keeping with the sleek contemporary decor that greets guests in the reception's glass-backed atrium. Refurbishment is under way but whichever type of room you book, the highlight will be the view. All have floor-to-ceiling windows overlooking the water, with private balconies from the second floor upwards - the higher the better. On one side, guests look across Cardiff Bay to Mermaid Quay and the city's skyline; on the other there's the marina, the Bristol Channel in the distance and a nearby nature reserve.

What's the food like? From the catch of the day to the rack of lamb or the house salad, the food at the Tempus at Tides (Tat) restaurant "reflects seasonal moods". Modern but relaxed, Tat is anything but tatty, and has earned a reputation as the place to go for city folk at the weekend, especially when there's entertainment in the bar. In the summer, guests can dine on the terrace, looking out to garlands of lights glistening around the bay. This being Britain, afternoon tea is a must.

We're refreshed and replete; what's next? Stroll around hip Mermaid Quay, lined with popular restaurants, visit the eco-friendly Welsh Assembly building on the waterfront and pose for the camera in front of the Victorian Pierhead and its "baby Big Ben". You could book a show at the Millennium Centre, home to the national opera, orchestra and dance company, or browse the craft shops or the latest exhibition at the Norwegian Church arts centre, which was originally built as a mission for Scandinavian seamen.

While regattas are held on the bay, another type of journey - through space and time - unfolds at the "Dr Who Experience". The long-running BBC sci-fi programme is just one of the many series and films shot in Cardiff and the Experience houses the world's largest collection of original props and artefacts from the show. The city is also home to the Millennium Stadium, which hosted 2012 Olympic events, as well as a medieval castle and elegant civic buildings. If you overindulge in retail therapy, the bowler-hatted doorman back at The St David's will be on hand to help with the bags.

What's the bottom line? Rooms start from £95 (HK$1,180) a night and run up to £495.

The St David's Hotel & Spa is on Havannah Street, Cardiff, Wales, the United Kingdom, tel: 44 2920 454 045; www.thestdavidshotel.com