Driving west along Prainha you will come to another beach surrounded by high hills covered in tropical jungle. It's a beautiful beach and it picks up the most swell of anywhere around. Even on the flattest days you can find decent surf at Grumari, and it can hold big SSW swells. The downside is that it is an hour drive from Ipanema, and worse if it's a hot weekend.There are several peaks along the beach, all having their day. The paddle out can be a bit tough, as the waves break on outer sandbars and reform. The crowd can be tough but not always. One of the most consistent spots on the coast, it's a great place to surf and hang out.
Source: Grumari Surf Guide