We got to attend as a guest, although they said the basic club membership could be purchased…read moremonthly at R$150 which included access to the pools and the tennis courts which they have several of. The classes offered at the pools such as master swim classes or water aerobics are extra fees. We were told one had to check in with the local doctor to be deemed fit for swimming in the pool, although the inspection consisted of a basic one minute look over and no questions asked.
The facility includes a number of things to do. At the entrance there is a museum (presumably of Flamengo history) which costs entry even for club members and is open to the public. Also open to the public is the huge Adidas store where one can get your hearts content of Flamengo paraphernalia, from specialty soccer jerseys to the latest fashion line of sports shoes. They even have a nice patio that over looks the (traffic and) the lagoa.
On the far left side they have a barbershop, small chapel, and another Flamengo store plus one of the many restaurants you can find food at. The swimming lanes are in the first pool, in which half is converted to a water polo court on certain days. Behind it in another pool and behind that is a huge an impressive gymnasium. It houses huge floor mats for Olympic routines, uneven bars, and vault. The latter two have deep pits, presumably are filled with foam during practice or people are harnessed and caught when they fall off.
Further back to the left is the medical office and the second entrance to the facility for members only. And still farther back is of course a soccer field. There's some stadium seating, and tennis courts all along the right side, both asphalt and clay courts, managed by the office in the corner. We weren't allowed to use them with our guest pass but at the very of negotiating, they finally allowed us since it wasn't very crowded (it was an overcast almost rainy day, and winter time). They also have another cafe on that side for drinks and snacks.
The kids pools are shallow (1.5m deep) and are sectioned off so the kids are not everywhere. There's a small kiddie pool for the little ones and some shorter lanes for those who don't need such a big space. There's a lanchonete in the middle of those pools, carefully surrounded by nets so no one can fall in or drop food into the pool.
Last but not least, the changing rooms were open, spacious, and clean. They had showers win hot water, toilets, lockers, benches and sinks. It was a good space for a lot of people but could get slippery if there was a lot of food traffic.
We did not explore the tunnel that leads to the rowing side though I think it looks awesome from the lagoa side.
Overall it was a good experience. The staff was friendly. If it were always this un-crowded it would be great!