First wash the oranges. With a sharp knife slice the oranges into thin circles. Then stack them and slice them into thin strips. Remove all the seeds
In a large saucepan bring the water, lemon zest, lemon juice and salt to boil and then add the oranges - segment and skin into the pot.
Let it cook till the fruit is very soft, about 45 minutes.
Once the fruit is cooked, add all the sugar. You will notice that the liquid jam start changing colour and becoming darker, don' worry, that's a good thing.
Cook the jam for about 20 minutes and then check for consistency by taking a spoonful of the jam and letting it run down a plate. If it's too runny it needs to cook for another couple of minutes, otherwise it should be ready by now.
Add the jam to a clean sterlized jar. Seal it completely. Then bring a large pot of water to boil and let the jars of marmalade boil for about 10 minutes.
Carefully remove the jars and let it sit to cool down. Open after 24 hours and your marmalade should last you for at least 6 months