We study absolute continuity of harmonic measure with respect to surface measure on domains Ω that have large complements. We show that if Γ ⊂ R d+1 is Ahlfors regular and splits R d+1 into two NTA domains, then ω Ω H d on Γ ∩ ∂Ω. This result is a natural generalisation of a result of Wu in [Wu86].We also prove that almost every point in Γ ∩ ∂Ω is a cone point if Γ is a Lipschitz graph. Combining these results and a result from [AHM 3 TV], we characterize sets of absolute continuity with finite H dmeasure both in terms of the cone point condition and in terms of the rectifiable structure of the boundary. This generalizes the results of McMillan in [McM69] and Pommerenke in [Pom86].Finally, we also show our first result holds for elliptic measure associated with real second order divergence form elliptic operators with a mild assumption on the gradient of the matrix.