Classes for handling points in a 2d Grid

Grid2d.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

public class Grid
{
    public List<Tile> Tiles;
    public int Width;
    public int Height;

    public Grid(int width, int height)
    {
        Tiles = new List<Tile>(width * height);
        Width = width;
        Height = height;
    }

    public Tile TileAtPoint(int x, int y)
    {
        return Tiles.FirstOrDefault(t => t.Point.X == x && t.Point.Y == y);
    }

    public override string ToString()
    {
        StringBuilder sb = new StringBuilder();
        for (int i = 0; i < Height; i++)
        {
            for (int j = 0; j < Width; j++)
            {
                Tile t = TileAtPoint(i, j);
                sb.Append(t?.Item);
            }
            sb.Append(Environment.NewLine);
        }
        return sb.ToString();
    }
}

public class Tile
{
    public Point Point;
    public string Item;

    public Tile(Point p, string item)
    {
        Point = p;
        Item = item;
    }
}

public class Point
{
    public int Y;
    public int X;

    public Point(int x, int y)
    {
        X = x;
        Y = y;
    }

    public int DistanceFrom(Point q)
    {
        double dx = X - q.X;
        double dy = Y - q.Y;
        var dist = Math.Sqrt(dx * dx + dy * dy);
        return (int)dist;
    }
}

Change Point to be struct and probably should use int here since its a grid.