This is the most famous trek within Torres del Paine, where you hike to the base of the towers for which the park was named. The last 1 km is almost straight up, with you scaling an exposed, sunny face of the mountain until you reach the rocky top. Before you reach the exposed section, you walk through one of the oldest growth forests within the park, which is lush, green, and canopied. You'll spot Calafate bushes and berries plus plenty of streams and bridges on the way. You'll also see gauchos on horseback going from the refugios in this mountain pass back out to the pampas. This trek is about 13 mi from EcoCamp (where I stayed), and you climb about 3,000 ft, which is the highest you'll likely go in Torres del Paine if you're just trekking. It's a very fun hike because it's so challenging, and of course this view at the top makes it that much better.