There are three entrances to the park: Laguna Amarga (all bus arrivals), Lago Sarmiento, and Laguna Azul. You are required to sign in when you arrive, and pay your entrance fee (around US$35 in high season). Guardaparques (park rangers) staff six stations around the reserve, and can provide a map and up-to-the-day information about the state of various trails. A regular minivan service connects Laguna Amarga with the Hostería Las Torres, 7 km (4½ miles) to the west. Alternatively, you can walk approximately two hours before reaching the starting point of the hiking circuits.
Although considerable walking is necessary to take full advantage of Parque Nacional Torres del Paine, you need not be a hard-core trekker. Many people choose to hike the "W" route, which takes four days, but others prefer to stay in one of the comfortable lodges and hit the trails in the morning or afternoon. Glaciar Grey, with its fragmented icebergs, makes a rewarding and easy hike; equally rewarding is the spectacular boat or kayak ride across the lake, past icebergs, and up to the glacier, which leaves from Hostería Lago Grey. Another great excursion is the 900-meter (3,000-foot) ascent to the sensational views from Mirador Las Torres, four hours one way from Las Torres Patagonia. Even if you're not staying at the Hostería, you can arrange a morning drop-off there, and a late-afternoon pickup, so that you can see the Mirador while still keeping your base in Puerto Natales or elsewhere in the park; alternatively, you can drive to the Hostería and park there for the day.
If you do the "W," you'll begin (or end, if you reverse the route) at Laguna Amarga and continue to Mirador Las Torres and Los Cuernos, then continue along a breathtaking path up Valle Frances to its awe-inspiring and fiendishly windy lookout (hold on to your hat!) and finally Lago Grey. The W runs for 100 kilometers (62 miles), but always follows clearly marked paths, with gradual climbs and descents at relatively low altitude. The challenge comes from the weather. Winds whip up to 90 mph, and a clear sky can suddenly darken with storm clouds, producing rain, hail, or snow in a matter of minutes. An even more ambitious route is the "Circuito," which essentially leads around the entire park and takes from a week to 10 days. Along the way some people sleep at the dozen or so humble refugios (shelters) evenly spaced along the trail, and many others bring their own tents.
Driving is an easy way to enjoy the park: a new road cuts the distance to Puerto Natales from a meandering 140 km (87 miles) to a more direct 80 km (50 miles). Inside the national park more than 100 km (62 miles) of roads leading to the most popular sites are safe and well maintained, though unpaved. If you stick to the road, you won't need four-wheel drive.
You can also hire horses from the Hostería Las Torres and trek to the Torres, the Cuernos, or along the shore of Lago Nordenskjold (which offers the finest views in the park, as the lake's waters reflect the chiseled massif). Alternatively, many Puerto Natales–based operators offer multiday horseback tours. Water transport is also available, with numerous tour operators offering sailboat, kayak, and inflatable Zodiac speedboat options along the Río Serrano toward the Paine massif and the southern ice field. Additionally, the Hostería Lago Grey operates the Grey II, a large catamaran making a three-hour return trip to Glaciar Grey four times daily as well as dinghy runs down the Pingo and Grey rivers. Another boat runs between Refugio Pudeto and Refugio Lago Pehoé.