ContactPoint.point  

// Print how many points are colliding this transform 
// And print the first point that is colliding.
function OnCollisionEnter(other : Collision) {
    print("Points colliding: " + other.contacts.Length);
    print("First point that collided: " + other.contacts[0].point);
}

using UnityEngine;
using System.Collections;

public class example : MonoBehaviour {
    void OnCollisionEnter(Collision other) {
        print("Points colliding: " + other.contacts.Length);
        print("First point that collided: " + other.contacts[0].point);
    }
}

import UnityEngine
import System.Collections

class example(MonoBehaviour):

    def OnCollisionEnter(other as Collision):
        print(('Points colliding: ' + other.contacts.Length))
        print(('First point that collided: ' + other.contacts[0].point))