rouelan

not sure of this (I mean the passport). Probably true that you should always have a form of ID with you, like a driving license or an ID card. As suggested by others, an internet search should tell what the rules are in Turkey.

thinking twice after reading other posts:
There are 2 situations when police may ask you to provide a form of ID. If you commit an offense or in case of random check to verify if your presence on national territory is legal. In the 1st case, at least in France, you are not fined on the spot and thus need to provide ID to send you the fine. In the 2nd case, I guess that a passport may be needed, depending on the country you are visiting and your nationality. Still in France, random checks have become a very sensitive issue and must abide to strict rules (for example, OK near a border, or take the opportunity of even a small offense, like not punching your metro ticket, to ask for your passport). As stated by other fodorites, if you look like a bona fide tourist and not an illegal immigrant, police is likely to be lenient in many countries if you don't show a passport.

rouelan

I regularly cross France Spain border by bus and such checks are frequent. Even on local buses in the area.
And it is the same experience, that is police barely checking the passports.
the reason is simple: they are after illegal immigrants but they cannot discriminate.So, they need to act as if they were checking everybody but it is far easier to detect an immigrant by the way he looks like.

danbiggie0342

Unless you're planning to rent a car or write traveler checks or do some other bank-related work, there's no need for your original documents and it's probably a good idea to keep it safely stored in your hotel room.