C# 总是在set处抛出 system stack over flow exception的异常是什么原因

namespace ConsoleApp1

{

class Program

{

static void Main(string[] args)

{

People tom = new People() ;

tom.Name =" Tom";

tom.Age = 18;

tom.MyPlace = Console.ReadLine();

Console.WriteLine(tom.MyPlace);

Console.ReadKey();

}

}

public class People

{

public string Name;

public int Age;

public string MyPlace

{

get

{

return MyPlace;

}

set

{

if (value == "北京")

{

MyPlace = value;

}

else

{

MyPlace = "不符合要求";

}

}

}

}

}