In my opinion Hiraizumi is rather boring. Even for someone like me who loves nature, the gardens and temples are very average and a big plain with a lake in the middle doesn't make me thing "oh wow, a world heritage site, it must be good!" or anything on that line. 

I arrived with a very early train before any of the WH sites are open and thus I took a taxi to the popular Takkoku-no-Iwaya Buddhist temple just outside of town. I remember it opens at 6:30am or something. Getting here without a taxi seemed not possible at this hour. Later on when I saw the rest of Hiraizumi I was shocked that Takkoku-no-Iwaya was the best of all and it's not inscribed. In the end I think it all comes down to some administration work and this extention will take care of it and make the overall Hiraizumi site better. I later found out that the temple was rebuilt in the 60s and nobody knew the original design so that is usually a problem as the sites should be authentic but it didn't take any pleasure away from my visit.