The new bridge, which was officially opened on 16 September 2009, connects Bonfim, Roraima, Brazil to Lethem, Guyana and Georgetown, the capital. This gives Brazil access to the Caribbean. The highway from the Brazilian border to Georgetown is not paved; however, plans are in the works to add this to projects Brazil is financing in Guyana.
From Boa Vista, Roraima, you can catch a bus to Manaus. From what I can gather, most people enter Roramia from Venezuela, which offers easier access to Brazil.