I am from Chile and I have a work visa for 9 months in the UK. I'm planning to take a trip from London to Istanbul, then to El Cairo, then to Athens, then to Barcelona, and finally come back to the UK.
However, I've heard that some countries' borders require a return ticket in order to enter the country. Is that true?
What other requirements do countries have for multi-country (and continental) trips?
Does it matter if I buy the flights tickets from different airlines?