The Pilis Hills are deep blue. Colours in the dry Hungarian air are already stronger and more intense than in England, and the high rolling wooded crests of the Pilis Hills shine a dark glossy shade under the strong southerly sun, above the lighter dales and valleys with their grassy meadows, rambling villages and bright fields of yellow rape, against a flawless sapphire sky. Occasionally, a landslip or quarry reveals a bright blaze of yellow-white where the underlying limestone is exposed, but the landscape overall is more mellow and rounded than the classical karst topography, with no stark cliffs or limestone pavements, though the hills are honeycombed with caves.
The Pilis Hills are supposed to be sacred. So says Wikipedia. I’m not clear yet why, but their deep color, shades of Marian blue, seems to be due to the thick shadows under the trees, so refreshing when driving with the sun’s glare beating off the tarmac. They do have a cloistered, awestruck air as they hang over the landscape, brooding and meditative.