Thermal baths in Iceland

Yes. The Blue Lagoon, Sky Lagoon, Secret Lagoon, Hvammsvík, Forest Lagoon, Laugarvatn Fontana, Vök and GeoSea all ask you to wash without swimwear before you go in. At the Secret Lagoon it's because the springs supply all of the water and no chemicals are added.

Several aren't. The Blue Lagoon renews itself naturally every 40 hours and needs no chlorine, the Secret Lagoon replaces its water every 24 hours, and Earth Lagoon Mývatn and Vök add no chlorine. At GeoSea in Húsavík hot seawater runs through the pools and over the edge into the sea, so no cleaning agents are used.

At most of them, with rules. Sky Lagoon admits no one under 12 and Hvammsvík starts at 10. The Blue Lagoon takes children from 2, in free floaties up to age 8, with at most two per adult, and Forest Lagoon has no under-12s after 20:00.

Destination Blue Lagoon buses run from Keflavík airport and Reykjavík hotels, and bus 35 goes to Sky Lagoon. Hvammsvík has a daily partner bus from BSÍ in Reykjavík, and Forest Lagoon a free evening shuttle from Akureyri. Strætó buses reach Laugarvatn and Reykjahlíð near the Mývatn lagoon, with few departures and some days without service.

A few. The hot tubs on the shore at Drangsnes in the Westfjords are free, with donations welcome, and so is Guðrúnarlaug at Laugar in Sælingsdalur near Búðardalur. Pollurinn, the natural pools above road 617 near Tálknafjörður, is free too, with a donation box. Hveravellir charges a service fee that covers the pool, toilets and showers, and at Landmannalaugar the summer fee is charged per vehicle for the hut's facilities, with no separate fee for bathing.

Landmannalaugar, yes, by highland bus in summer: buses run from Reykjavík, Selfoss, Hella and Leirubakki, and there's none in winter. Driving there needs a 4x4 on the F-roads, with river fords on the last stretch. For Hveravellir on the Kjölur route, the operator says no scheduled bus runs at the moment.

Mostly: no soap, no glass and take your litter away. At Hveravellir you shower before getting in, bring your own towel and stay on the marked paths, because the hot springs around the pool can be dangerously hot. At Landmannalaugar you keep to the wooden walkway across the bog, and at Drangsnes you shower in the cubicles across the street before using the tubs. Pollurinn has no toilets, and camping there is forbidden.

Pools fed by hot springs on the Strandir coast and on the fjords further west. In Strandir there are the Drangsnes hot tubs, Gvendarlaug, a lukewarm pool beside Hótel Laugarhóll in Bjarnarfjörður, and Krossneslaug on the shore at Norðurfjörður. Further west, the country hotel at Heydalur lets non-guests use its greenhouse pool and hot pots, Hellulaug lies on the shore of Vatnsfjörður near Flókalundur, and Pollurinn looks over Tálknafjörður. Gvendarlaug has no pool attendant, so children bathe on their guardians' responsibility.