How to declare an array of array in c# mongo db models?

I am making a function using Azure Functions and Azure Cosmos db (mongo db api) and i need to make a model for the data. One of the fields need to be a array of array but I cant find how to declare an array of array for a method

This is my model

namespace GeofencedLocations.Models
{
    public class Geofence
    {
        [BsonId]
        [BsonRepresentation(BsonType.ObjectId)]
        public string LocationId { get; set; }
        [BsonElement("Location name")]
        public string LocationName { get; set; }
/// this is where i need to declare an array of array
        [BsonElement("Location Coordinates")]
        public string LocationCoordinates { get; set; }
        [BsonElement("user ID")]
        public string userID { get; set; }
    }
}

Location Co-ordinates will an array of array, something like this in json

 {
   "lat" : "000'00",
   "lon": "000'99"
 },
 {
   "lat" : "000'00",
   "lon": "000'99"
 }

]