Budapest, Hungary: Beautiful baths amid ornate architecture

Budapest is not only one of Europe's most enjoyable city breaks, it's also a great place to embark on a river cruise. Flying into the Hungarian capital the day before beginning a voyage on the Danube, you may be too shattered (OK, jet-lagged) for sightseeing. Chances are you'll want to check into your hotel and go for a lie-down. Don't do this. It'll play further havoc with your body clock and you'll board the ship the next day in even more of a daze. My advice: when in Budapest, and in need of a pick-me-up, go to the baths.

Split by the Danube, the city is perched on a patchwork of more than 100 hot springs. "Taking the waters" has long been a tradition here, with the ancient Romans, Ottoman Turks and Habsburg royalty among those to have wallowed in the area's aquatic pleasures. Visitors today can choose from an array of thermal baths and medicinal spas that tap into the mineral-rich springs, with many venues flaunting wonderfully ornate architecture and attracting a cross-section of Budapestian society.

The biggest and most popular is the Szechenyi Baths, which dates back to 1913 and sprawls across City Park on the Pest side of the river. Set around a complex of yellow, palatial neo-baroque structures is a series of pools heated up to 38 degrees, where you'll rub bare shoulders with everyone from Hungarian pensioners, who play "water" chess here, to body-beautiful millennials posing for selfies using their waterproof smartphones. Most Saturday nights are "sparty time" with DJs, laser effects and alcoholic drinks (served in plastic glasses).

The wellness options on the Buda side of the Danube tend to be more chilled-out though just as toasty. Built in the 16th century during the Ottoman occupation of Budapest, the Rudas and Kiraly baths both convey a medieval aura, especially in their atmospheric, octagonal pools, which are framed by stone arches and tucked beneath domes etched with slits that let sunlight trickle through.

Walk 10 minutes beside the river from the Rudas Baths, in the shadow of the steep, wooded Gellert Hill, and you'll find arguably Budapest's most opulent bathing draw: the Gellert Spa. Like the hotel it's connected to – the imposing Danubius Hotel Gellert, a favourite stay of kings, presidents and famous composers – this maze-like spa is a feast of art nouveau design. Floors and walls are clad in mosaics, there are soaring marble columns and fountains, colourful stained glass, lush potted plants and nude sculptures. There is a mix of indoor and outdoor pools, which, bar a few cooler options, are mostly heated from 33 to 40, perfect for sinking into and letting the water work its magic on your jaded mind and muscles.

As with many of Budapest's antique spas, the Gellert has seen better days. It was built between 1912 and 1918 and rebuilt after World War II damage but remains a beguiling place in which to while away an afternoon. Bring thongs to navigate the labyrinthine corridors and slippery inter-pool areas and a swimming cap if you'd like to swim lengths of the 28 degree main pool, which is surrounded by chairs where bathers lounge and read books. You can also delve into dark, aromatic steam rooms, indulge in pampering treatments such as massages and pedicures and take refreshments at the spa's cafes and eateries.

Leaving Gellert Spa relaxed, refreshed and a happy kind of tired, I return to my hotel (the superbly-located Sofitel Chain Bridge), drop my bathing gear and stroll for dinner at Zeller Bistro, one of Pest's excellent new wave of eateries.