6.5-mile, with 1,250-foot elevation gain loop hike with breathtaking views of Lake Tekapo, the Southern Alps, and the Mackenzie Basin on it's way to the silver domes that house the telescopes of the Mount John Observatory atop the summit. The summit of Mount John is part of the Aoraki Mackenzie International Dark Sky Reserve, renowned for its exceptional stargazing conditions because of the lack of light pollution. It's a working astronomical research observatory and it’s very popular for the Dark Sky Project’s stargazing tours, where visitors see the night sky through the powerful telescopes within those domes.