What Are Sink Holes and why are they formed? It will be amazing if one finds a big hole near the house which is not there the last night. Those kinds of holes are called as sink holes which are caused due to the sudden depression of the earth in one place. Though the effect of these sink holes is more in many places it is too much and often seen in the Florida of America. Here are some of the details of those dangerous holes. In some areas, the layers of the lime stone will be more when compared to the other areas. When rainfall is there, the water goes inside the earth and the lime stone is dissolved. So at that time, the earth will be depressed at that area and there forms a big hole which is called as sink hole. These holes may range starting from one meter to some thousands of meters area. There is some thousands meters of lime stone placed under the earth in Florida. besides that, the underground rivers are more in Florida. As that water is passing in the underground, the lime stone which is there in the earth is getting dissolved and there happens forming of sink holes. One may get doubts that whether these sink holes do not form in any other place on this earth. The answer for this is they will form. The largest sink hole was formed in Egypt. The name of that sink hole is Khattara Depression which is 80 Km length and with 120 Km width which is formed in a desert. The sink holes are of two kinds. One of the kinds is which are formed from many years and some which are formed suddenly. For example, one of the sink holes which is formed in Russia in the year 1986, has depressed 200 meters depth and 40 meters width and is increasing even today. One of the sink holes in Texas has depressed to around 900 feet in a day to the amazement of all the people. The sink holes are not seen only on the earth but are formed even in the water. In some of the situations, there are situations where the earth under the water will be depressed and the water enters into that hole. The Zecatan sink hole of Mexico is of the same kind. The depth of that sink hole is 318 feet, which is almost equal to Eifel tower. There is no problem if the sink holes are formed in the deserts, forests and in the rivers. But if they are formed in the areas where people wander is really problematic. At that time, even the houses which are constructed with lakhs of money will get drowned into that sink holes. In many areas, the people suffered from these sink holes and many lost their lives too. In some areas, there rise the situations where the people have left their areas and migrated to other places.