If you only have time for one temple, then make it Zentsū-ji, number 75 of the 88 Temples and the place where Kōbō Daishi was born. The temple boasts a truly magnificent five-storey pagoda and giant camphor trees that are said to date back as far as Daishi's childhood. Visitors can venture into the basement of the Mie-dō building and traverse a 100m-long passageway (戒壇めぐり) in pitch darkness.
By moving carefully along with your hand pressed to the passageway's wall (painted with mandalas, angels and lotus flowers), you are said to be safely following Buddha's way.
If you're on a bike, there are several other pilgrimage temples within easy reach of this one, including Temple 73, Shusshaka-ji. The temple is about 1km from the JR Zentsuji Station, straight ahead as you exit.
