From the World Heritage inscription:
The Bahá’i Holy Places in Haifa and Western Galilee are inscribed for their profound spiritual meaning and the testimony they bear to the strong tradition of pilgrimage in the Bahá’i faith. The property includes the two most holy places in the Bahá’í religion associated with the founders, the Shrine of Bahá’u’lláh in Acre and the Shrine of the Báb in Haifa, together with their surrounding gardens, associated buildings and monuments. These two shrines are part of a larger complex of buildings, monuments and sites at seven distinct locations in Haifa and Western Galilee that are visited as part of the Bahá’i pilgrimage.
Unfortunately, I visited the Baha’i gardens on a Baha’i holy day so the gardens were closed to visitors. I was able to take some photos from the top of the hill where the gardens are located (Mount Carmel) but that was it. If I am ever in northern Israel again I will make sure to return to the gardens to explore them more thoroughly.