The Grotto is an appendant body of regular Freemasonry. Its full name is “Mystic Order of Veiled Prophets of the Enchanted Realm” or MOVPER for short. The members wear black fezzes with red tassels, and the local groups are organized into “grottos”. To become eligible to join one has to be a Master Mason in good standing (dues paying) in a local lodge. It is a social organization that encourages Master Masons to enjoy fellowship, brotherhood and engage in charity.
The Grotto was formed in 1890 and is still very much focused on friendly fellowship and charity. It offers a Persian themed atmosphere, degrees and titles. It is often compared to the Shrine. But while the Shrine required its members to be either 32 degree Scottish Rite or Knight Templar York Rite members (this was only changed in the year 2000), the Grotto was open to all Master Masons.
In 1917 the “Mysterious Order Witches of Salem” was formed as the female auxiliary body of the Grotto. To join, one must be the wife, widow, or female relative of a member of a Veiled Prophet.
More Info:
https://scgrotto.org