Iron is a very important mineral. It helps to transport oxygen around the body and is also needed for immunity, cell regrowth, energy, and development. Most people will get enough iron from eating meat, breakfast cereal, fruit, and vegetables.
Watermelons have been around for a while having been originated from Africa and then coming to Asia around 900 AD and to Europe 1300 AD. They were first used to stop dehydration as they contain around 90% of water. They have dark green skin and red flesh and are more beneficial when ripe. They contain many vitamins and minerals. They are rich in iron especially the seeds and are one of the fruits that are the richest in the mineral.
Eating a watermelon can be beneficial as you will still get your iron intake but it does not have as many calories as eating red meat which is also a good source of iron. A slice of watermelon will provide you with around 2% of your intake which is around 0.4 milligrams. The average male or female should have around eight milligrams per day so you would either need to eat many slices or else substitute it with other things to ensure you get your daily intake.
Eating watermelon will provide you with iron but not much and you should consider eating red meat and spinach which will provide you with a greater intake.