probably the biggest obstacle is altitude sickness. walking,
treking or climbing is very much dependent on you but a fittness
will be a plus. One more "obstacle" for many of us will be toilet.
Put away your expectation and you will really have fun.
Other places I visited are
1) India - The four primary places of the Buddha
http://www.sgforums.com/forums/1769/topics/299292
2) Sri Lanka - where Therava Buddhism flourished when it almost
disappeared in India,
http://www.sgforums.com/forums/1769/topics/331806
3)Cambodia - Angkor Wat, where Buddhism is greatly influenced by
Hinduism when India invaded them.
http://www.sgforums.com/forums/1769/topics/264231
4) Nepal - where Hinduism has also greatly influence Buddhism,
however today, the Tibetian is having a great impact to Buddhism
there.
Pls feel free to comment
Envy you guys who have been to so many places. Have you
thought of Bhutan which is also a Buddhist country. It
seems that now is the trend to go there. I have seen the pictures
of Bhutan, it seems that it is still remained "untouched" by the
outside world.