Guarapari

Guarapari's beaches carry monazite, a phosphate mineral rich in thorium that weathers out of the surrounding rock and concentrates in dark patches on the sand, particularly at Areia Preta. The result is a background radiation level far above the world average - among the highest recorded on any inhabited beach - and for much of the twentieth century this was marketed as therapeutic, with visitors coming to bury themselves in the sand for supposed relief from arthritis and other complaints. There is no evidence for the benefit, and modern advice is simply not to spend prolonged periods lying on the darkest patches. The town is otherwise a straightforward Brazilian beach resort with a long seafront, and Praia do Morro is the main strand.

What you actually see

• Black monazite sand - thorium-bearing mineral concentrated in dark patches.
• Very high background radiation - among the highest on any inhabited beach.
• A discredited health claim - the sand baths once sold as treatment.
• A standard beach resort - Praia do Morro and the long seafront.

When to go

October to March. Two days.

Honest expectations

The radiation is real and unusual but is not a reason to lie on the black sand for hours; the historical health claims have no support. The town is crowded and loud in summer and quiet out of season. Beaches near the centre are not the cleanest.

Nearby

Vitoria and Vila Velha are north; Anchieta is south down the coast.