603-352-2299br Keene Events. Martial Arts Principles Grand ReOpening Celebrationbr br Want a day of fitness & fun for your family? Join us at Martial Arts Principles for our Grand Re-Opening on August 27th at 233 Marlboro Street Keene. We will have outdoor kid & adult classes for your family to join in, martial arts demonstrations, a bounce house, picnic lunch, and so much more.