Please feel free to play around with the number of days in each place and add cities or remove cities.

Anything is "possible".

However I don't know what you mean by "play around with the number of days" - do you have more days to spend in each place or do you have a set number of total days?

Without knowing your likes and dislikes and the reason why (family? friends?) you want to be in one location (Crete) for so many days, it's hard to comment.

Off the bat, I'd say that you're spending too little time in Paris and Istanbul and too much time in Crete.

Also when you travel from one city to another, you've lost pretty much one whole day - you need to get from the city to the airport and at least an hour or two before flight time, then there's the actual flight time, then there the time to get from the airport to your hotel.

If you could furnish us with more details, we could dialog further and refine your plans.

Looks terribly rushed to me, with little time " on the ground" anywhere except Crete. Why don't you just go to Greece and Turkey and maybe Rome and enjoy those venues? Paris and London seem like afterthoughts. You're going to spend a lot of money to get to/be in London and Paris for absolutely negligible amounts of time.

If I were you, I wouldn't spent only 2 days in London, I would dedicate at least a week for it

I would skip Paris, its not worth it for 1 day here, and add that time to London.

And then skip Istanbul and add that time to Athens and Rome.

I, OTOH, would skip London and add days to Paris; skip Athens and spend more time in Istanbul, which is a truly amazing city.

See? What are YOUR likes and dislikes? Not what our likes and dislikes are.

You're going to Istanbul and Paris for 1 day each? It's a waste of time and money to get there and see almost nothing. But it's your money and your time. I would remove Paris and Istanbul because it seems that you have little interest in either city, based on the amount of time you've scheduled in them.

I certainly would not add any more locations to this list since you have a short time in Europe.

I would eliminate both London and Paris and add a day to Rome and the rest to Istanbul. Note that you have many and varied suggestions but since we don't know what you like and why you have chosen these particular cities, we are choosing our itinerary, not yours.

Help us to help you.

Thank you all for your comments, I guess I need to tell you guys more. A friend and I are going to Europe this summer and we have between 20 to 30 days and we want to see as many places as possible. We also wanted to spend a good amount of time relaxing in the Greek islands and we chose Crete for 5 days. We both enjoy archaeological sites but we wanted to also enjoy the amazing beaches of the southern Aegean Sea. We have both been to Athens and Zakynthos before but did not spend much time in Athens so would like to go back. My friend is dying to sea Paris and we also have some friends in London. I hope this helps a little more.

Thank you for clarifying.

It does not change my view that you have too much for that amount of time. Trying to see as many places as possible means you will spend a lot of time and money moving around in transit as opposed to actually seeing the great things in the places you are.

If you want to see Paris then devote the time to it. 1 day is hardly worth the expense of time. It would be better to accept that you will be back to Europe again and leave it for next time if you dont want to give it more time this time around.

Unfortunately we all have to prioritise when we plan trips - not everything fits in given the time restrictions.

If your goal is to see as many places as possible then it doesn't matter where you go since you're only looking for quantity. You can add Amsterdam or a few cities in Italy to your itinerary.

If your friend is "dying to see Paris" then you'll only get a look at the city in 1 day; your friend won't be able to experience Paris which is a different thing than just seeing the city.

My goal is to see places in depth rather than for a short time.

Would 5 nights in London, 5 in Paris, 5 in Rome, and 5 in Crete be a better option to explore all those places?

5 nights in each of those 4 places will at least give you a fighting chance to see them.

Absolutely.

20 days is too rushed. With 30 days you could expand on the number of days in Paris and Istanbul.

Your age matters too. Barcelona and Berlin (both not on your list) are cities good for young people - not that they don't have a lot for older people or for people who want to visit museums, but there are vibrant European cities which are especially attractive for young people.

Or take the Mediterranean Sea - plenty of wonderful places to go to besides Greece - the south of France, Croatia...

One of the best ways to stretch your days in Europe is to take the night sleeper train. You can sleep on the train at night (which will save you one night in a hotel, if savings is important to you) and enjoy the next city by day. This take careful planning, as you do not want to change trains in the middle of the night. However, you could zigzag around Europe by taking night trains.

So much more to talk about The more you tell us of your interests and of yourself, the better information you will from this website.