Reverse String In C#

using System;
namespace reverseString {
    class Program {
        static void Main(string[] args) {
            string str = "", reverse = "";
            int Length = 0;
            Console.WriteLine("Enter a Word");
            //Getting String(word) from Console  
            str = Console.ReadLine();
            //Calculate length of string str  
            Length = str.Length - 1;
            while (Length >= 0) {
                reverse = reverse + str[Length];
                Length--;
            }
            //Displaying the reverse word  
            Console.WriteLine("Reverse word is {0}", reverse);
            Console.ReadLine();
        }
    }
}