  Monte Carlo algorithms such as the Wang-Landau algorithm and similar
`entropic' methods are able to accurately sample the density of states of model
systems and thereby give access to thermal equilibrium properties at any
temperature. Thermal equilibrium is however not achievable at low temperatures
in glassy systems. Such systems are characterized by a multitude of metastable
configurations, pictorially referred to as `valleys' of an energy landscape.
Geometrical properties of the landscape, e.g. the local density of states
describing the distribution in energy of the states belonging to a single
valley, are key to understand the dynamical properties of such systems. In this
paper we combine the lid algorithm, a tool for landscape exploration previously
applied to a range of models, with the Wang-Swendsen algorithm. To test this
improved exploration tool, we consider a paradigmatic complex system, the
Edwards-Andersom model in two and three spatial dimension. We find a striking
difference between the energy dependence of the local density of states in the
two cases: nearly flat in the first case, and nearly exponential in the second.
The lid dependence of the data is analyzed to estimate the form of the global
density of states.
