THE FACT ABOUT GROUP TRANSPORT FROM İSTANBUL AIRPORT THAT NO ONE IS SUGGESTING

They have got a designated compartment for baggage, so you will not have to carry your bag in all places like you do when taking an IETT bus or metro.  Honestly, I never ever use a private transfer from Istanbul airport to the city center because I usually journey with my boyfriend Otherwise solo, so the Havaist bus looks as if a terrific selecti