We show that the group factors LΓ , where Γ is an ICC lattice in either SO(n, 1) or SU(n, 1), n 2, are strongly solid in the sense of Ozawa and Popa (2010) [13]. This strengthens a result of Ozawa and Popa (2010) [14] showing that these factors do not have Cartan subalgebras.In their breakthrough paper [13], Ozawa and Popa brought new techniques to bear on the study of free group factors which allowed them to show that these factors possess a powerful structural property, what they called "strong solidity." Definition 0.1. (See Ozawa and Popa [13].) A II 1 factor M is strongly solid if for any diffuse amenable subalgebra P ⊂ M we have that N M (P ) is amenable.As usual, N M (P ) = {u ∈ U(M): uP u * = P } denotes the normalizer of P in M. It can be seen that every nonamenable II 1 subfactor of a strongly solid II 1 factor is non-Gamma, prime and has no Cartan subalgebras. Thus, Ozawa and Popa's result broadened and offered a unified approach to the two main results on the structure of free group factors hitherto known: Voiculescu's [29]