A nimble marmoset dangles upside down by its hind legs, enjoying a banana at Forte Duque de Caxias in Rio de Janeiro on December 13, 2024. Visitors can reach the top of Morro do Leme (Leme Mountain) via an 800-meter steep trail that winds through the lush Atlantic rainforest. Also known as Leme Fort, the stronghold was constructed between 1776 and 1799 during Brazil's time under Portuguese rule. (Photo by Bob Karp/ZUMA Press Wire/Rex Features/Shutterstock)
