Expires 4 months after purchase. Limit 1 per up to 8 people, may buy 3 additional as gifts. Booking required online at http://puzzlingadventures.com/purchase.php; select location, follow the steps through to the payment section entering Groupon security code into the promo box. Present Groupon on arrival. No cancellations once booking has been made. No age restrictions, but under 18s must be accompanied by an adult. Approximate duration 90-240 minutes. Approximate distance is 3 miles for the London and 1.5 miles for Cambridge and Edinburgh. Must be able to walk for up to 240 minutes on unpaved surfaces: mostly flat, but with sections of steps, grass, sand or dirt. Access to smart phone and mobile internet necessary to complete the adventure. Valid 7 days a week 9am-6pm. Valid for option purchased only. Verified using our merchant's website on 7 Feb 2019.