As you know holly books use symbolism to express some abstract concepts to be understood easily by ordinary people. So they objectify these concepts and make them more understandable. For example in the bible sometimes stars represent those who radiate light, spiritual instruction(1) and sea represents restless masses of society, usually unruly and lawless.(2) Main question here is heaven and hell are also symbols or real places? Let´s see what two most well known İslamic scholar say about this matter.

İbn Sina (980-1037) who is known as Avicenna in the west tells(in his work "eş-Şifa") that human mind is not fully capable of understanding some abstract concepts and sometimes it needs concrete examples to fully comprehend them. He tells heaven and hell are symbols and there are not a garden-shaped heaven and a hell consists of fire.(3)

İbn Tufail(1105-1185) tells (in his philosophical novel "Hayy Ibn Yaqzan") that considering symbols same with symbolized things can confuse and misguide us. He tells, divine substances are beyond objects and they have no relations with them. They can only be described symbolically. So hell and heaven are only symbols.

If they are symbols what they mean? I think hell is a cage(metaphorically) which a person puts himself/herself in because of his/her blindly attachment to material things and heaven is a situation of a person freed himself/herself from this attachment.

(1) http://www.revelation-today.com/A1Bible%20Symbols.htm#Stars
(2) http://www.revelation-today.com/A1Bible%20Symbols.htm#Sea
(3) Dodurgalı, Abdurrahman, İbn Sina Felsefesinde Eğitim, İstanbul 1995, p. 181

There is hell and there is heaven. By saying that these are only symbols you are making God a liar. There has to be separations there, because there is a Judgement Day. Like in courts the judge decides either you go to jail or you are free. The verdicts are true and not symbolic.

The Bible says things clearly. However, you are right we arent able to tell how heaven and hell look like.

Do not tell lies to yourself. There is an afterlife. Everything will come to an end. You will be judged. Then you will either go to heaven or hell. Do you have your soul saved?

As an atheist I´m going to argue there is neither heaven nor hell and the end of life on earth means the end of live full stop. Believers take all the "knowledge" of the afterlife from their Holy Scripts, ie they base their whole life on books written a long time ago, whcih have proven out-of-date several times. If I were to analyse the text as a document, I´d say the authors had to come up with an ultimate punishment and reward, otherwise people would not want to follow the rules. If they had come up with "divine" punishment and rewards to happen within one´s lifetime, they would have been proven wrong in no time. That´s why the reward and punishment that cannot be proven. It´s your choice - you either choose to believe a book or you choose not to. If you choose to believe then you should believe in heaven and hell.

It´s interesting to see how differently particular groups interpret the same words. I can speak about the Bible only, I don´t have enough knowledge about Qran. As far as I can remember, Catholics believe in hell, heaven and purgatory. And hell is usually portrayed as a pretty hot place with cauldrons of tar hanging over fire. Jehova Witnesses believe hell means death and no resurrection on the Judgement Day. A defined number of people will go to heaven, as soon as all the spaces are occupied there will be Judgement Day and the good ones will take the Earth and the bad ones will remain dead.

 I believe afterlife. And I also believe our obsessions will not let us go until we get rid of our attachment to material things. For example a mingy person who only gives importance to money will be more obsessed when he dies and becomes a soul because he wont have money anymore. This will be his hell until he accept this. As you can see he has to be his own savior if he wants to get out of his hell. He is the one who will judge himself. Because he is also a part of god.