This weekend is the last chance to see the many faces of Mami Wata, and if you choose, to leave an offering for her, as well. An exhibition about the water spirit (Mami Wata means “Mother Water” in pidgin English) is on view at the Smithsonian’s National Museum of African Art. The exhibition closes this Sunday, July 26.

Over time, the deity Mami Wata has become a blend of cultures and religions, influenced by Hinduism, Islam, and Christianity. At the museum, an altar glistens among the paintings and sculptures that depict her with a mermaid-like form, flowing hair and grasping a snake. Even though the altar has not been consecrated, or blessed, visitors have been moved to leave offerings.

Powder has been sprinkled across the bottom tier, while a hair brush, star-shaped swizzle stick and charms from a bracelet have been left behind on the altar. Coins have been rearranged and spread out on the lower tier. The only gift that was removed was a fresh plum, because food is not allowed in the galleries, explains chief curator Christine Kreamer, and would have attracted insects.

The altar is a recreation of a shrine owned by modern-day priestess Mamissi Pascaline Acrobessi Toyi in Ouidah, Benin (a country west of Nigeria). Traditionally, Toyi blesses all the offerings during a seven-day rite of singing, dancing, purifying, blessing and fasting. The items that were installed on the altar as part of the museum exhibit are examples of Toyi’s offerings. One that catches the eye is the miniature plastic guitar, which is explained in the signage with a quote from Toyi: “It is with music that Mami is content… If you play the guitar and sing she will be happy… She loves to go to nightclubs.”

Clearly, the visitor offerings, inspired by the power and lore of Mami Wata, are a testament to the exhibition’s impact.

“Visitors have certainly interacted with the altar as if it were a functioning, dedicated altar, and there continues to be great interest in this water spirit and the arts dedicated to her,” Kreamer said.