Seoul has quietly become the place to fly for your skin. Treatments there typically run 30 to 50 per cent cheaper than in the UK, Europe or the US, and plenty of them — from salmon-DNA skin boosters to multi-step head spas — aren't available outside South Korea at all. The Independent's Hayley Spencer spent half a trip testing the scene and came back with a shortlist.

Start with the most local of experiences: a jjimjilbang, the traditional bathhouse that doubles as a social hub, with steam rooms, salt rooms, charcoal saunas and many open around the clock — handy when you land eight time zones out of sync. Book a seshin body scrub and prepare to be thoroughly exfoliated. Women-only Spa Lei in Gangnam charges about £8 entry plus £22.50 for a scrub; near Incheon airport, Paradise City CIMER spans six floors including a virtual spa room with LED scenery.

For jet lag and post-flight puffiness, a lymphatic drainage treatment worked wonders at Art de la Peau in Myeongdong — around £130 for 90 minutes combining acupressure, a plasma device and a vitamin mask. Korean therapists are known for deep-tissue technique rather than gentle pampering, but the sculpted, lit-from-within results are the point.

Hair is treated as seriously as skin. EcoJardin's tourist-friendly flagship offers an 18-step head spa (£190) beginning with a scalp diagnosis under a digital microscope and featuring the viral steam-inflated 'mushroom cap' that opens the follicles. Haircuts run roughly 40 per cent below UK prices, so it's a smart place for a cut or a K-pop-worthy digital perm.

Another Instagram fixture worth doing in situ is personal colour analysis, where an expert maps your skin, hair and eye tone to a 'season' of flattering shades. Big Olive Young stores organise makeup by these colour categories, so getting analysed first makes shopping there far more useful — the N Seongsu flagship does it free if you arrive early, while Colorize Store in Myeongdong charges about £80.

If the choice paralysis is too much, beauty concierges such as Aneue (from £1,122 for a white-glove itinerary) will build a schedule, provide translators and match you with clinics for tweakments like Rejuran, Xerf or Oligio. One thing that sets Seoul apart, per London aesthetic doctor Christine Hall: clinics analyse hydration, pigmentation and elasticity first, so treatments are personalised rather than one-size-fits-all.

For beauty-focused travellers, this is a genuine reason to add days to a Seoul trip — and to time your first appointment for touchdown day. Virgin Atlantic flies direct from Heathrow to Incheon from £889 return; the design-led Mondrian Seoul Itaewon has rooms from £200 including breakfast.