The temple is indeed beautiful but the surroundings are stunning as well: Mount Merapi is only a few kilometers away!
If you have already visited the Angkor temples in the kingdom of Cambodia, there is a good chance that you will feel a bit disappointed by Borobudur (I know I was because I was there in Nov 2010, right after Mount Merapi's eruption which heavily affected the site because of the ash)
A huge compound of Buddhist stupas overlooking a deep Javanese forest. It seems very rough at first sight, but it is so ancient that you have to be stunned by its beauty and meaningful design.