Most people visiting Macchu Picchu will get the bus from Aquas Calientes and the just wander around the site. Not a problem for most people of average fitness. There are lots of steps, many of which are very steep. The hike takes 3-4 days and you do need to be fit and acclimatised to the altitude. The train is the best way to get to AC but needs to be booked in advance.

You can definitely enjoy the site without a strenuous hike. Like crellston said, there are two ways to get to Machu Picchu: 1) A 2- or 4-day hike on the Inca Trail and 2) a bus ride up the mountain from Aguas Calientes. The bus takes you on a switchback road up the side of the mountain Machu Picchu sits on. The site itself does have many stairs, but you can take them at your own pace and opt to not climb to certain areas.

Also, you are able to bring walking sticks into MP. Officially they say only if they are medically necessary, but I saw many people of all fitness levels using them. Just make sure they are wooden or have rubber tips (if they're metal).

To see the iconic view from the "Watchman's Tower" you need to be able to walk up an inclined ramp and rough stone steps. However you do not need to hike. You will see many seniors there, just take your time going uphill. I would recommend going on your third day after arrival to adjust to the altitude. I would also stay in the Sacred Valley first, not Cusco. Ollantaytambo is a pleasant little town and where most of the trains depart from.

If you cannot ascend to the Watchman's Tower viewing platform I believe they will let you enter to the right which is the more level part of the site, and you will still be able to see the site from inside, just not the overview that you see in photos.

I took my 73 year old Mum on the Classic Inca Trail and she did the 4 day trek! She just took it all very slowly. As everyone says above you can get the 20 minute bus ride up to the site and the buses leave from Aguas Calientes from 05.30AM. The site is on levels and the view that you mention is walking back up to the sungate (you will see many sweaty Inca Trailers walking the other way towards you!!). You can do it if you take your time, even if you make it half way up you will get some great views a little bit away from the masses.

I see they removed the post from the fellow who has hiked to Machu Picchu 750 times. It did look like advertising so I understand the decision.

I hope he can figure out a way to post within the rules. He was our guide on the Inca Trail and he was fantastic.

cold, if you post his name and company then it presumably would be okay.

Mlgb - I am sure you are right. But before you posted I had sent a message to the editors asking them if I could post the guide's address. No answer yet. I am waiting to see how long it takes, though I suspect my question never arrived.

So I got the go ahead to post. The guide's name is Raul. He has started his own agency:

http://www.alpacaexpeditions.com/

As I said in our trip report, Raul is a legend on the Inca Trail. He seemed to know everyone from every tour company.