Save up to 39% Off & 1st Child Free Grand Sirenis Riviera Maya Hotel & Spa, Mexico. Save up to 39% when Book on Sirenis website your stay at Grand Sirenis Riviera Maya Hotel & Spa from August 26 to October 31, 2015. This fantastic price includes an extra discount for booking a non refundable rate. T&C: Booking Period:Now until September 4, 2015. Staying Period: From August 26, to October 31 2015. Book Now.