Forte Duque de Caxias, a working military base in Leme, is open to visitors. For just BRA$4, visitors can climb up to the top of Morro do Leme to see a historic fort along with stunning views of the city. The fort is open daily except Monday.
It takes about 20 minutes to reach the top of Morro do Leme and it’s not a difficult walk. If you’re lucky, you might spot monkeys on the way. The walk is through a protected natural area, which is a small remaining part of the Mata Atlântica (Atlantic Rain Forest).
Once at the top, there is a historic fort museum which isn’t of much interest. I was able to walk through the hallways and see different parts of the fort. The fort was originally constructed in 1776 and was named Forte da Vigia. It was built in response to a Spanish invasion of Portuguese-held Colonia del Sacramento, now in Uruguay. It was renamed Forte Duque de Caxias in 1935.