Flagstaff is a city in northern Arizona. It is the governmental center of the Coconino County and home to the Lowell Observatory and the University of North Arizona. The city has a population of about 60,000 people, and is along Route 66.
The hostels in Flagstaff are reasonably priced and are a common staying place for travelers before heading to one of the world-famous nearby attractions, the Grand Canyon (which is about 75 miles away). Many Flagstaff hostels will organize these trips for the people staying, so you should ask them for details if you're interested.
Well known as a place for people who like the outdoors, the terrain (which is very varied), high elevations and elevation changes, and nice weather have attracted backpackers and travelers from afar. Hiking and biking are very good options (or skiing if you're around in the winter). There are also golf courses and spas in Flagstaff, and if you're willing to pay the price, you can take a helicopter ride to Grand Canyon. There is also some art and culture / theater attractions.
Flagstaff is also home to the famous Flagstaff Brewing Company, which was founded in 1994. The company produces world-class hand-crafted ales and lagers, and is a very nice place to visit if you enjoy a cold beer.
The main city area is compact and easily walkable. The city is also served by buses and trains that you can use to access your hostel in Flagstaff, but having your own car or a rental is a huge advantage when considering mobility.