the longer of the two, called
circular outer archer trail
(trilha circular externa major archer), is about 35 kilometers
long versus the shorter of the two, called
castro maya trail
(trilha circular interna castro maya)
that is about 15 km long.
the castro maya inner circular trail is the most popular of the two, being slighter
easier due to lower altitudes, and being designed to reach a
variety of interesting sites, including several caves.