Arise, and proclaim unto the entire creation the tidings that He Who is the All-Merciful hath directed His steps towards the Ridván and entered it. Guide, then, the people unto the garden of delight which God hath made the Throne of His Paradise. We have chosen thee to be our most mighty Trumpet, whose blast is to signalize the resurrection of all mankind.
Bahá’u’lláh, Gleanings from the Writings of Bahá’u’lláh
Behold how within all things the portals of the Ridvan of God are opened, that seekers may attain the cities of understanding and wisdom, and enter the gardens of knowledge and power. Within every garden they will behold the mystic bride of inner meaning enshrined within the chambers of utterance in the utmost grace and fullest adornment.
— Baha’u’llah, The Kitab-i-Iqan
Today is the first day of the Festival of Ridván. Bahá’ís around the world celebrate this festival:
“Ridván is a twelve-day festival in the Bahá’í Faith, commemorating the commencement of Bahá’u’lláh´s prophethood. It begins at sunset on April 20 and continues until sunset, May 2. On the first April 21st, ninth April 29th and twelfth days of Ridván May 2nd, work and schooling is suspended. … It is the most holy Bahá’í festival, and is also referred to as the ‘Most Great Festival’ and the ‘King of Festivals.'”
(from the Wikipedia article about Ridvan)
Shoghi Effendi, the Guardian of the Bahá’í Faith, described it as “the holiest and most significant of all Bahá’í festivals.” The event that the Ridván festival commemorates took place in 1863 in Baghdad. Above is a photograph (which I colorized for this page) of the original Garden of Ridván.
Download a document from the Bahá’í Writings and other sources about the broader symbolic significance of Ridván’s meanings as paradise and reunion with God (seven pages) including a brief historical background of the festival (two pages).