Pre-booked tours only, maximum 10 people per tour.
Two tours per day.
April: 4th, 14th, 18th and 28th
May: 2nd, 12th, 16th and 23rd
June: 2nd, 6th, 16th and 20th
July: 4th, 14th, 18th, 28th
August: 4th and 15th
September: 5th, 15th, 19th and 29th
October: 3rd, 13th, 17th, and 27th