I was specifically thinking of Zanzibar, but any other island in the Indian Ocean would be good for the relaxing beach holiday I have in mind. Best bet is anywhere in the Seychelles. That is, if you can handle humid tropical heat and mosquitoes - but at least there's no malaria or any other serious tropical diseases there.
Hotels are expensive but guest houses can be reasonably cheap and are clean.
The best Seychelles beach is Anse Lazio on Praslin. June is towards the rainy season on the west coast of India. I'd think carefully before parting with my money, if I were you.