How fit do I need to be to do this trek?
Annapurna Base Camp is a Grade B or a moderately difficult trekking route. So any fit person can do this trek, even if you do not have any previous experience. You should be aware of what to expect and mentally prepare for it. Then, as long as you will too, you can.
What about battery charging and hot shower facilities?
Yes, you can charge batteries en route. Charger should be brought. There are hot shower facilities as well. You may have to pay a certain amount for both ($1-$2). Negotiate. Also, a hot water facility could be free at a lower elevation.
Are there ATMs on the way to Annapurna Base Camp?
No. There are no ATMs on this trek route. You will have to draw enough cash in Pokhara or Kathmandu. There are a number of ATMs in these cities. Everything is paid in Nepali rupees. So money should be exchanged before the start of the trek.
What about internet access?
Yes. The Internet can be accessed in most places. Sometimes, there might be some technical problems. The Internet in Nepal is not as fast as you are used to and at times you can just lose connection.
Is it necessary to hire Guides/trekking agency for Annapurna Base Camp trekking?
Not really. It depends on you. If you want, ABC trekking can be done independently. You could hire a guide and a porter by yourself instead of going through an agency or not hire a guide at all. Although, not having a guide can be a little problematic during the offseason.
It really depends on you. Is it your first time in Nepal? How confident are you of being able to find your way around? How pressed on time are you? If you go through an agency, it will be costlier but everything will be planned. You will only have to come, trek and return.
