This is perhaps one of the most misunderstood concepts about the alternative hikes and treks in Peru. Do these hikes let you walk in to Machu Picchu? No. But they all include a visit of Machu Picchu.

People think that when the Inca Trail is sold out they can book one of these alternate hikes and still hike in to the ruins. It's not your fault that you think this! Operators advertise alternative hikes TO Machu Picchu. I would think that means you get to hike in. But. That is not the case. All the alternative treks end in Aguas Calientes and usually there is an overnight in a hotel. The next day hikers take the shuttle buses to the main entry with the travelers who arrive by train. (I'm not counting the ride on the shuttle bus and walking through the main entry gate as "hiking to Machu Picchu.")

There is only 1 path that literally take you in to the Machu Picchu National Park on foot.

That path is the Inca Trail. Whether you hike 5-Day, 4-Day, 2-Day, 1-Day, Easy Hike or the Short Hike. They all funnel to the same Sungate and a single path takes you down to into the national park. From there you can exit and go to the village if you plan to come back for a separate guided tour of Machu Picchu. Or you can hike in to the park, then enter the Machu Picchu citadel for an up-close guided tour of the ancient city. The Inca Trail requires advance permits which can only be purchased by a tour operator. Permits allow the park authorities to contral access to the national park. There are checkpoints at various stages of all the Inca Trail hikes to ensure that everyone on the trail that day: 1) has a permit and valid passport,      2) is accompanied by a licensed guide. 

The only other way to get to Machu Picchu is by train to Aguas Calientes, then a 25 minute bus ride from the village to the main entry (you can also walk from the village to the main entry. But unless you have plenty of time, I would rather spend my time inside the ruins, rather than getting to the ruins. The walk is not picturesque and intersects with the dirt road used by the buses all the way up the mountain) The main entry is where the majority of visitors will enter.

There are a lot of hikes on the internet that advertise "Alternative Hike TO Machu Picchu." The thing you need to understand is that this is a misleading title. What it should say is, "Alternative Hikes WITH Machu Picchu." No matter which hike you choose, Salkantay, Lares Valley, Cachiccata (Quarry), or any other hike that advertises hiking TO Machu Picchu, they will all go through the village of Aguas Calientes. Sometimes you get there by train from Ollantaytambo or Hidroelectric stations. Or walk from hidroelectric. But the end result is the same. You finish the hike at the village and just like all the people traveling by train to Aguas Calientes, you will take the shuttle bus (or walk to the main entry). 

What about the Mountain Lodges of Peru "lodge to lodge" trek?

They advertise that you trek to Machu Picchu. That is misleading. The trek ends in Aguas Calientes and then you take the shuttle bus to Machu Picchu. 

Does the Inca Jungle route go directly to Machu Picchu?

No. The jungle route ends in Aguas Calientes. And like all the other hikes and treks you will take the shuttle bus (or walk) to the main entry of the national park.

If Inca Trail permits are sold out, it's usually for the 4-day (which includes the 5 day) hike. Permits for the 2-day Inca Trail typically don't sell out (although they can!) But because there is no camping on the 2-day trip, many people are looking for alternate trails and multi-day hikes to Machu Picchu. There. Are. None.  

In case anyone has heard that you can get a view of Machu Picchu while hiking Salcantay Trek, yes you can. But it's a distant view and does not include entry to the ruins. 

Do you have to go to Machu Picchu? 

No. You could end your 3 or 4 day hike in Aguas Calientes and return to Cusco. This would not be common but it can be done. We have have people come back to Peru just for the hikes. It's a nature-lovers paradise. You don't have to go to Machu Picchu.

What's a girl to do if she wants to do a multi-day trek TO Machu Picchu, and enter on foot, but permits are sold out?

We designed an itinerary that combines 3 days of hiking Lares Valley, Cachiccata or 4 days Salkantay, with 1-Day Inca Trail. It's really the best of both worlds. Hiking and camping and entry TO Machu Picchu on foot.